The term anti-social behaviour can mean many things to people.  Generally, anti-social behaviour can cause nuisance, disorder and harassment.

The Crime and Disorder Act, 1998 formally defines anti-social behaviour as acting:

"in a manner that caused or was likely to cause harassment, alarm or distress to one or more persons not of the same household as [the defendant]"

Anti social behaviour can ruin lives and can make the community you live in unpleasant and frightening, resulting in more serious crime taking place.