why can't this be done?

[TekillaSunrise]

Please, set up a hackshield.

[Corak_the_Mysterious]

Please, set up a hackshield.

This was tried in the european version. It does stop some of the more obvious hacks, although obviously it can't do anything about exploits that are continually found in a game that doesn't get patched. All it ended up doing was causing a lot more crashes and slowdown. It also killed some sandbox programs, which is good or bad depending on your viewpoint, but in the end virtual machines were still useable so it only stopped people with low end computers from stacking a million alts.