When I filed my last DS-160 for my final H-1B renewal before I got my green card, I remember filling in my social media identifiers. In fact, a look at a 2019 document reveals that providing the identifiers has been required since at least back then[0]. Given that the identifiers must be offered, the intent must be that the posts should be read, so this is unsurprising[1].

I suppose one happy fact from this must be that USCIS has never had convenient access to dragnet surveillance. For if they did, they would simply have used the backdoor rather than ask you to make the profile public. For my part, I always assumed that the US Government knew everything I posted.

I'm sure that if they didn't like me for some reason, they'd find a Richelieu accusation to make from what I've written. One would imagine it is like that other self-evident thing in the First Amendment, "separation of church and state", that is also practiced where convenient and not otherwise. Unless born American (and perhaps now, also "to Americans born American") some degree of scepticism for the tenets of the American Civil Religion will serve anyone well.

0: https://travel.state.gov/content/dam/visas/Enhanced%20Vettin...

1: I'm sure someone could construct machinery where a blacklist is produced by one arm of the government with view to posts which is used by another arm that which has no post-access but I think that was unlikely when this was designed