OP, and other people that have been "cheated", would you mind posting some games here ? (without the names of your opponent) And be sure to indicate the point at which you believe the guy started the engine.
I would be happy to debunk the myth that 99% of players above some level are cheaters.
who cares if your being cheated? get real
It isn't about losing a few rating points that will easily be recouped through more play, it's about the principle of the matter. If everyone in chess cheated then it would devalue the game as a whole and render playing meaningless. It's the same reason why cheating on a test is wrong: if everyone cheated then the test would be rendered meaningless and lose its value. If everyone doing a certain thing would be wrong then it's wrong if one person does it.