Many people in the London riots were using BBM to coordinate rioting or looting.

http://www.theguardian.com/media/2011/aug/08/london-riots-fa...

http://www.telegraph.co.uk/technology/blackberry/8688651/Lon...

Blackberry claims to help police.

http://www.theguardian.com/technology/2011/aug/09/london-rio...

http://www.forbes.com/sites/parmyolson/2011/08/09/blackberry...