T-Mobile: Are you blocking specific words and suspending accounts?

https://reddit.com/r/tmobile/comments/i1fk1z/tmobile_are_you_blocking_specific_words_and/

by QUFB • 6 years ago

167 55 6 years ago

reddit.com

Someone1234• 6 years ago

There's two different but both problematic things here:

- Really poorly written spam detection.

- Failure to notify customers/no remediation procedure.

No doubt people will bring up "but then the spammers will know!!" Or similar, but honestly spammers are already limited by the cost of buying SIM cards ($5/ea), and I feel like customers being negatively impacted outweighs the minor benefit to spam-fighting (particularly when spammers could buy a single second number and detect this 100% of the time anyway).

Plus I'd be pretty upset if I was a customer paying for service, and I lost access to a part of that service for 10 days because I sent the word "butt" in a conversation. I'd feel particularly irritated if I wasn't told that my messages weren't delivered, and vital ones were just going into a void.

drtillberg• 6 years ago

For SaaS like Strava or something, I'm agnostic whether the notice should come before the shut-off alleging a TOS violation. For cellular service though, SMS is integral to life. 911 even accepts SMS. Imagine T-Mobile silently dropping 911 SMS communications because someone texted the wrong word? Which isn't even in the TOS?

This is like dangling chum in the water, waiting for a big shark to chomp your leg, T-Mobile and whatever individual engineer came up with this.

ThePowerOfFuet• 6 years ago

Did anyone allege that sending SMS to 911 was affected?

makethetick3• 6 years ago

Bulk SMS spam would most likely come from someone with direct signalling access and not from individual SIM cards which would be trivial to detect and block by the operator.

Geezus_42• 6 years ago

The only SMS spam I ever get is from email addresses...

jasonjayr2• 6 years ago

It is trivial, even for someone not that technically oriented to send a mass SMS from Android, with the appropriate app. Since it's easier to sideload on Android, it would be even easier for a malicious spammer to pay people to install sketchy APK's that spam from the user's phone relentlessly.

jcrawfordor• 6 years ago

I think there's an increasing amount of SMS spam being sent by random compromised consumer devices, which is probably what drove T-Mobile to take this sort of desperate measure. It would seem like notifying the customer is even more warranted in this case, though.

nullc• 6 years ago

which would be trivial to detect and block by the operator.

Problem solved! https://www.aliexpress.com/item/4000124061983.html

Scoundreller• 6 years ago

Bell and Telus in Canada we’re doing this. But only if your SMS contained the term « secure message ». Strange to say the least.

lgats• 6 years ago

do you mean 'we are doing this' or 'were previously doing this' ?

chevman• 6 years ago

T-Mobile has also not been approving new short codes on their network since earlier this year. Frustrating for folks trying to execute legit SMS comms.

toomuchtodo2• 6 years ago

Use case(s)? I’ve have success working with financial services firms moving their comms from short code to push notifications in app. Always curious who is still using bulk SMS and for what.

ryukafalz2• 6 years ago

As someone who dabbles in alternative mobile OSes (and would like to switch to one full-time again soon), it's frustrating when there isn't a fallback option to standard protocols. Thankfully email/SMS are still fairly ubiquitous, but I don't like the idea of that going away for something important like banking and being locked into one of the big two platforms.

zachrose2• 6 years ago

I’ve been developing SMS chatbots and using my T-Mobile phone for testing. They will also drop messages that contain URLs, although the rules for which TLDs are allowed are hard to reverse engineer, much less rationalize. Last I remember, .club URLs are blocked, .com is allowed, and bit.ly is allowed.

foob• 6 years ago

I recently ran into this sort of filtering when trying to share an AI Dungeon .link URL with a friend. It's kind of crazy that entire TLDs are blocked without any indication or warning.

vincentmarle• 6 years ago

Hmm I suspect this could be related to Branch links, because their default deep link domain is app.link

willvarfar• 6 years ago

Tangent: tell us about your dungeon! How does it work, are you happy with it etc? Links you can share?

Show HN of course!

ta1234567890• 6 years ago

Verizon also blocks messages based on the urls they contain. Not sure about specific TLDs, but surely whole domains. Discovered this by running a service that sends a lot of messages through Twilio. Not sure if you would ever be notified of the block when sending from your phone.

In my opinion is not really to block spam, but instead to push message senders to buy the carrier's more expensive shortcode option.

rsync2• 6 years ago

... which can’t be reached from twilio, since twilio Numbers are not actual mobile numbers.

jasode• 6 years ago

From the scant details about the word "BELLY" triggering the blocks, it looks like some hypothesize it's a "Scunthorpe" type of programming bug:

https://en.wikipedia.org/wiki/Scunthorpe_problem

jessaustin• 6 years ago

I don't see "cunt" or any similar string anywhere in the string "belly". As mentioned at TFA, this is more likely some sort of naive Bayes filtering since "belly" is often seen in "lose belly fat fast!" etc.

tyingq5• 6 years ago

The article reads like it's much less sophisticated than Bayes. Perhaps just "x messages that have belly in them over y time period". Where either x is too small, or y is too big.

LanceH• 6 years ago

I would guess it is aimed as "reduce belly fat" spam.

dogma1138• 6 years ago

Are US carriers even allowed to do this?

speedgoose• 6 years ago

Facebook Messenger does the same with some porn links.

Hippocrates• 6 years ago

This is a great reminder to switch from SMS to something that is e2e encrypted.

gallego2007• 6 years ago

I was thinking the exact same thing. I need to convince a few family members to ditch SMS... unfortunately some businesses (like apartment buildings) still use SMS to communicate, so it’ll probably be a while before we fully move away from this medium.

tyingq5• 6 years ago

PayPal has a similar problem. They do really loose string matching on the OFAC list[1], for any data, in any payment field...even a comment. Match a magic string in a comment, and your PayPal account gets locked down in a way that's very hard to undo.

[1] https://www.treasury.gov/resource-center/sanctions/sdn-list/...

andybak• 6 years ago

How loose is the string matching? That list looks full of incredibly common names from around the world.

WrtCdEvrydy2• 6 years ago

that's what the SDN list really is, just some common names of people, organizations and countries.

it's up to you to figure out how to turn that into not selling to the wrong people and going to prison.

tyingq5• 6 years ago

It seems pretty damn loose, but of course, it's hard to test since the outcome ruins your PayPal account. I found this: https://m.imgur.com/a/RnpRm

WrtCdEvrydy2• 6 years ago

Because there's no downside to doing it this way while a lot of upside for 'being tough on terrorism'.

Good luck if someone sends you a payment for 'Cuban food' or 'Iranian Weapons of Mass Destruction'

Shank• 6 years ago

There’s already a story about Venmo seizing money from someone who used “ISIS beer funds” in a comment: https://www.inverse.com/article/13700-i-wrote-isis-beer-fund...

vultour• 6 years ago

Yeah this was a big thing back in the heyday of CSGO skin trading. Putting the word "damascus" into a transaction comment would get your account locked.

myself248• 6 years ago

Which seems inept, as "Damascus steel" is a sought-after material for knife blades.

timeinput• 6 years ago

I ran into this a few months ago when texting the phrase "work from home" it was really strange. We rationalized it with the spam / phishing thought process, but it still seems wrong for the carriers to block messages so poorly.

It makes me wonder if I really want them filtering 'spam' calls.

tinfoil hat maybe that's their end game!

dzhiurgis• 6 years ago

“Learn to code” is harassment on twitter

dredmorbius• 6 years ago

https://old.reddit.com/r/tmobile/comments/i1fk1z/tmobile_are...

wdr1• 6 years ago

TL;DR: spam detection is hard

njarboe• 6 years ago

Charge people not in your contact list 10 cents to message you. 5 cents goes to you and 5 cents to the carrier. Problem solved. I would love this for messages and phone calls (and emails while we are at it).

simonebrunozzi• 6 years ago

T-mobile is a joke. I lost my @simon Twitter account [0] because of T-mobile's and Twitter's utter incompetence, and it took me more than 3 months to regain control of it.

The way the attacker gained control of my phone number should have never been possible. I'm still a customer, why? Because there's no better alternative in the US, although I'm pondering Google Fi at the moment. Thoughts?

[0] https://medium.com/@simon/mobile-twitter-hacked-please-help-...

organman91• 6 years ago

It's just a single phone, but google fi has worked pretty well for my use case. I was impressed how well it worked when I went on vacation to Canada last year. If you don't need to have a half-dozen devices on one account there's really very little that gets you as much bang for your buck - unless I'm really burning through data my bill is usually $30/month.

woofie11• 6 years ago

If you don't mind losing your phone number forever, Google Fi is a great option!

If Google Pay suspects fraud, it locks your account. Google Fi isn't paid for. Google locks your phone number from being ported out forever. Empowered human support wouldn't be Googley, so it's usually locked out forever.

T-Mobile isn't very competent, but at least, they provide humans who can fix things, eventually, once they figure out what they're doing.

T-Mobile: Are you blocking specific words and suspending accounts?

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