Facebook's Fake Followers

This isn't normal fake accounts. This is describing some kind of long-term strategy to get accounts into groups:

> the accounts will often not post at all (though they may perform innocuous actions such as likes) for up to a couple of years after joining, only after which they begin posting spam: they are sleeper accounts.

Makes me scared for the groups I'm in.

Has anyone else seen this?

Author here: I have a feeling this is getting lost in /new, but I think the content will be very interesting to HN: it discusses spam accounts on Facebook and a new tactic they seem to be using in one group I moderate.