bootstraping

Article link without paywall: http://archive.today/UAYFP

It seems they are (or slowly will start) charging all high volume users. Read this happened with Cloudflare too...

What makes them think they should start charging now?

Also, have you looked at hcaptcha.com? Cloudflare uses them.

For me, it's the reverse. Kernel usage spikes when I use the top right port for charging. It's fine if I use the left ones.