Bike theft and violence

While I don't know much about the incident, my first instinct would be to treat it as a mugging and, despite the fact that the bike was taken, I wouldn't think that a flash ride would be an appropriate response here. We could give out information to park users, ideally together with police and park authorities, and obviously better enforcement is key (much as it's unlikely that there'll be more, similar attacks there while the culprits lay low). Tower Hamlets Wheelers may be interested in following it up:

http://www.wheelers.org.uk/

Hmmm. Giving out leaflets won't raise the media profile, a Flash ride might.