Back in the old CS 1.5 me and my friend would just go to lan centers and clean house, we got thrown out a couple of times because people said we were hacking and it was like prove it. Eventually we went stared playing online from our homes and there were a couple of times I just got insanely lucky kills and people just flipped out screaming hax. Which really sucked because I'm a person who loves finding a server I like and constantly returning. I got banned from a server I played on for like a year because on one round it was a 3 on 1. One guy came at me from the front and the other from behind, they thought it was a guarantee kill so the guy behind tried to run up behind me and knife me. I hit the guy in the front with a headshot, turned around to get behind cover in case he had backup, the guy behind filled my screen and just reflexively I shot and kill him. Apparently they thought I spun around way too fast and shouldn't have known he was behind me. Then running around for a minute or so I thought I heard a guy ahead so I lobbed a grenade around a corner and it miraculously killed him. People screamed hax and that I wouldn't have thrown a nade unless I had wallhacks on. I got banned and pretty much never played CS again.
Nowadays I play games mostly for recreation and don't have much time to be slightly better than average, using a cheap headset, and a cheap mouse, I really don't get accused of hacking ever.