

Grab those comments and repost them in a place where you are more comfortable. You can keep that knowledge out there without needing to keep your account if you don’t want to. Some of those apps actually give you your comment history in a file when they’re done.
They’re sequential, so the values above and below yours are valid SSNs of people born in the same hospital around the same time.
This would make it trivially easy to get access to records you shouldn’t