redstron

Nothing stops one creating a fake Facebook profile. Choose a reasonably human sounding name, crank the privacy levels way up, and comment. FB is unlikely to figure out it's fake.

There are some disadvantages. Your fake identity will probably need to be reused across sites, since creating a new account involves getting an email address, which takes a few extra minutes per identity. But choose a generic enough name, and it is less of a problem...

This already happens. Groups and pages that would be classified as "hate" are magnets for obviously fake profiles, which are often friends with other fake (and real) profiles. Facebook's real-name policies seem to be poorly and arbitrarily enforced. The more sites that use FB for commenting, the more innacurate FB's social graph will become.

Fake accounts get shut down very quickly

I have encountered numerous fake profiles that have survived for months/years. Many of these represent businesses that should really be pages. Others are accounts that are used on hate groups/pages exclusively and have highly offensive fake names.

The worst example I've seen was a vicious cyberbullying profile that Facebook allowed to accumulate hundreds of friends, under an obviously fake name, despite a large number of abuse reports.