Early in my hosting days, I had four girls party in my space, on their last night. Just themselves, but alcohol was involved. This isn't the general notion of what might consitute them "throwing a party". Probably in line with the notion of "enjoying themselves".
They caused quite a lot of damage by getting drunk. Broke a caster off the roll-away bed, slammed the bathroom door so it split, left rings on furniture, and bottles everywhere.
My policy, now, is, of course, "no parties or events", but also "no alcohol allowed on the premises".
While I can't prevent people going out and drinking, at least I can try to prevent them staying in and drinking.