Lots of people are cheating on chess.com with computers. However, most of them don't. Many are becoming seriously paranoid about these cheaters, to the point where they accuse people of cheating without real evidence.
I've been playing a few games recently and everytime I beat someone over 300 points higher, they accuse me of using computer assistance. I've recently played someone named Renumerated Frog who had about same rating as I did (around 1550). I beat him and he started spamming me with messages about how it was so pathetic to cheat in an unrated game. Did he even bother to check the game on Fritz first?
Here is the game:
The game was full of numerous blunders from both sides. Any player would tell you that it was not the work of a computer. The game itself is actually of bad quality and played in 3 minute time control.
Its fine to have comtempt for cheaters but don't accuse someone of using a computer unless you have real evidence. Also, don't do it just to make your opponent feel bad after he/she beat you. Sore losers are probably just as bad as cheaters.