As Ath192 notes, genuine anti-cheat software is extremely invasive. The only area in which I'll subject my PC to that is from online poker clients.
That said, it is possible to spot many cheats without the GMs sticking a thermometer up your butt. In other words, rather than probing for banned software, it is possible to see the results of that software through motion (in the case of speed hacking/teleporting) or patterns in and timing of button presses in the case of scripting. Why more isn't done in this area I have no idea.