The idea was that impersonating a federal agent or law enforcement official was a felony, which among other things, even if you did your jail time, would result in you being in the system, on speed dial for actual law enforcement, and bereft of certain fundamental civil rights.
Of course, there is still the issue that all that serves to do is keep honest people honest, and doesn't do much to deter a determined criminal who is certain they'll get away with it, criminals who don't care and just want to do as much damage as they can before being stopped, etc...
In truth, you can't do much about it short of public access to operational details of Law enforcement agencies, which arguably comes with it's own set of problems.
Hence, now the country being in the midst of a crisis of faith, all thanks to the absolutely jaw dropping incompetence and unprofessionalism perpetrated by the Administration, the Legislature's complete ineffectiveness and incapability to follow any other strategy than "pitch impossibility and deadlock", and the Media not even being able to be relied upon to show some decency in terms of holding the bar of ethical journalism high enough that enough people can trust them without having to cross-reference to next Sunday to get a reasonably accurate rendition of what actually happened.
While others may advise the 2nd Amendment, which I wholeheartedly support, it doesn't solve the immediate need of satisfying due process without escalating to violence in the event of a lawful arrest.
Of course, if you're a protestor,even a lawful arrest may not carry that much weight for you, and at the end of the day there is something extremely uncomfortable about a state of affairs where you end up either arresting unarmed Protestors, and shooting/ignoring the armed ones.
Can't deny that fundamentally speaking though, individual to individual: only you can ultimately be responsible for keeping yourself alive, breathing, and free. Act accordingly. If you accept that puts you on the wrong side of the law, then that's that, and maybe one day that can stop being the case, and the struggle continues. If it puts you on the side of enforcing the will of the People you deem to be legitimate, that's that; the struggle continues.
If you just want others to leave you be, to live and let live, you need to be prepared to fend off getting wrangled in by either of the aforementioned groups, and just as above the struggle continues.