The blame lies with the cheap airlines. If flights to Krakow were more expensive there would be no lager louts and stag parties.. simple as that.
Well in a way they too are responsible but banning cheap flights would only hurt the normal hard working conscientious person too. Basically the Police need to have a zero tolerance approach to these idiots, if they step out of line when visiting any country then they should be arrested for breach of the peace and banged up for a few days and deported, this means that they will not be allowed back into the country. Infact I feel that if people are travelling and cause trouble there should be a points system, just like a drivers licence. For minor offences like peeing on the street it could be 3 points and a £60 on the spot fine and points given depending on the seriousness of the event Too many points then they take away your passport.