Anti social behaviour

"Behaviour by a person which causes or is likely to cause harassment, alarm or distress to one or more persons not of the same household as the perpetrator." is the definition of anti social behaviour according to Brentwood Borough Council, they also believe any behaviour that is unwanted by others can come under this definition, but what constitutes as unwanted behaviour?? The local youth which live by me usually hang about on the greenery by my house, recently they have been issued with ASBO's just for standing there, as apparently it is unwanted behaviour by some of the surrounding residents, but is this action really neccesarily?? If it was a group of adults standing around there would it result in the same action?

http://www.brentwood.gov.uk/index.php?cid=599