A less common, but I'm seeing more frequent tacit are user accounts where they delete their posts after X time so the account looks like it has been around, but you've no idea where / what was posted.
Those users almost always head down the rabbit hole after a few posts....
It should be difficult to get in or at least have some reputation system built-in like StackOverflow. Proof that you behave and have valuable opinions. It is quite bad if thousands of bots can be made easily and post spam, fakenews and manipulations.