Guards are sick sh*t of them as well and not much they can do as most are under 18, courts give a slap on the wrist and they out doing same thing a few hours later.
Only way to deal with these scumbags is get their details and give them a right good beating.
It's happened over past few years and it causes it to go quiet for a while until next batch of them come along.
I remember seeing a post on FB a few years ago, the lads robbed the wrong car... The Cork 32 CSM had up a post, family members bike was taken and they got it's safe return in a disciplined manner and they will reject this anti social behavior in their area.
There has been a few bike gang members bikes taken too and they have recovered them with warnings given.
Best way to deal with these fellas is going after them in your own time, plenty of videos of them taunting guards etc