Of course that promptly shifts the potential for abuse in the other direction. Supposedly, democracy is the control over that. If they are abusing their office, you vote them out. (Or you vote out the elected official supervising them, such as a mayor or sheriff.)
It actually does work out most of the time. The cases of abuse are really few and far between. But in a country of 300 million, "few and far between" is somebody every single day, and a decent chance that it's you at some point.
That said, it should be zero, and there's good reason to think that for every offender you see there are dozens or hundreds of people complicit in allowing it. The theory I outlined above can only handle so many decades of concerted abuses before they become entrenched as part of the system. At which point it may be impossible to restore it without resetting everything to zero and starting over.
If an agency has shitty officers doing dodgy stuff, it's on the agency. The agents may be declared immune to direct litigation, but any claims and reparations should be automatically shifted to the agency.
(a) Social media operators choose to do nothing at all against coordinated influencing operations, unless the influencing goes against the interests of very specific countries and groups.
(b) US government most likely has unfettered access to social media data. As if this isn't bad enough, they will probably give them out to Palantir for "data integration" and under uncertain terms.
Because I really can't recall anything outrageous, and surely nothing on the level of surveilance existing in the UK.
But OTOH, if Trump is erratic enough to trigger a world-wide de-dollarization trend, and close down markets that were traditionaly open (e.g. Europe), then US would be facing an unprecedented storm that would be much harder to navigate.