Note that activities which are potentially suspicious aren't just about posting, it includes following people, because that makes their follower count go up, and the whole point of displaying that count is most people want to appear popular - and so of course people create bogus followers.
I agree that Twitter using this to get people to give them PII those don't want Twitter to have, especially when Twitter aren't a good custodian of that PII is terrible, but it's not as though Twitter's other option (anybody can mint a thousand bogus Twitter followers with no pushback from Twitter) looks great either.
I agree that Twitter using this to get people to give them PII those don't want Twitter to have, especially when Twitter aren't a good custodian of that PII is terrible, but it's not as though Twitter's other option (anybody can mint a thousand bogus Twitter followers with no pushback from Twitter) looks great either.