The hackers suck on this game big time. If you can find a reputable server, they usually control hackers much better. I play one one that's pretty well managed, but if they suspect hacking of any sort going on, the server goes down until they can find the logs to prove someone used a hack, and then ban them. This is good because it discourages hacking, but the server tends to go down often and usually for an hour+.
Lately the most recent glitches have gotten more annoying to me than hackers. Like randomly falling under the ground, swimming, then spawning on the coast without a single item. If you look where you were when you disappeared, there is a clone of you standing there that you cannot interact with, but you can loot all of your stuff back normally.
Also, passing out on stairs and breaking your bones.
Gaining bandit clothing, and having it disappear after about 5 minutes after login. When it disappears, it makes you switch weapons, and refills all of your ammunition for some reason.
Another thing would be the graphical glitches caused by dead bodies, barbed wire, and other items in military locations.
Despite all of the glitches and hackers, I still love this game. This is one of the best PC games I have ever played with friends by far.