Probably by the phone number used for account verification, in many cases

The anime avi posters will have to level up their OPSEC

Literally all data coming in/out of the US (lots of it, even between other countries sometimes routes in-between US network transit points) is kept, and considering the possibilities that just private companies have today by dealing with data brokers and others offering "social media protection" (or whatever they call it today), it's hard to even imagine what the government and its agencies can do.

Did we really forgot about what happened back in 2013 so quickly? Did people assume all these agencies suddenly stopped doing what they've been doing for decades? Nothing you do on the internet with regular network connections are hidden to these entities, don't live falsely under the impression that you can.

The answer to that question doesn’t change the sage advice to not lie.