South West Trains opens prison?

Just checking for updates on the train and tube services, since I imagine I'll be in for another roller coaster ride home this evening owing to the surprising confirmation today of the existence of weather, and I came across this gem on South West Trains web site:

"14:24 Portsmouth & Southsea to London Waterloo due 16:13

This train will no longer call at Clapham Junction.  This is due to disruptive passengers."

Does not stopping at a scheduled station somehow prevent passengers from being disruptive (rather than, say, inconveniencing all the non-disruptive passengers on the train who (a) wanted to get off at Clapham Junction or (b) would have preferred disruptive passengers to be removed rather than be forced to endure their company for another stretch)?

And speaking of stretches, did I miss the announcement that South West Trains were now operating mobile prisons?  Answers on a postcard, please.  Or the comments, if you're too cheap to buy a postcard.