Talking about bike pictures brought to mind Bike Shepherd a website which stores your personal details and photos of bikes you have in the event they are stolen http://www.bikeshepherd.org/ . This coupled with stickers you can buy and can be scanned via a smartphone allows the Police to return the bikes to their owners.

£9.99 for a set of 3 stickers against having your bike stolen is a good investment in my opinion.

Arguably the stickers could be pulled off but the thief might not know what they are.