Back in school the "fun" thing was to steal people's entire handlebar/stem/levers/shifter setup with one allen key and some cable cutters. That could easily be a couple hundred bucks right there to replace. So we would drop hot solder into the allen head to prevent easy removal. When you needed to change the stem you could just re-heat the solder with the soldering gun and push the allen wrench in (displacing the hot solder).

This worked well for my campy c-record crank one bolt release too.