This was being discussed on Jeremy Vine this lunchtime - specifically the role of "the internet" [Jeremy Vine is clearly a luddite, much like the rest of the Beeb]. As was pointed out by several callers, gatecrashing (especially of teen parties) is nothing new - word-of-mouth just means a bit more these days. Anyone stupid/naive enough to post a party invite ON A BLEEDING PUBLIC WEBSITE needs their head examining. If she'd posted flyers all over town would Jeremy Vine be wittering about "the role of paper in today's society"? Gah.