Counter-Strike: Source, also known as CS:S has been around for awhile now, and has had changes along the way. Some of which may have been for the better others maybe not. This has always been a favorite of mine when it comes to FPS, but I think it may be dying out.
Even with the anti hacking program people still get away with hacking while playing and using cheats/programs that allow them to do many things. Seeing through walls is one of them, as well as speed hacking, aimbot, and some programs even play mp3's while you do all of these things.
I have also recently heard that Valve's anit-hacking program wrongfully banned over 30,000 or so accounts. I think we may see a decline of CS:S in the coming future.