Controversial encounters between law-enforcement and civilians - the omnibus thread #2

I’m a bit confused.

Does this mean that any federal agents can do absolutely anything they please at any time, even when off duty… full stop? Anything, and they are immune from prosecution? One of them could rob a bank, kill the tellers and guards, take a pile of money and … Immunity? They just keep the money?

Or are they just allowed to threaten anyone they like with a gun? Where’s the line for what crimes they are allowed to commit?