My saddle has been stolen

I parked my bicycle in front of the flat of a friend of mine, then my saddle had gone when I went there to buy some more alcohol.
There had been no accident with my bicycle except for puncture, so I thought the security of London was not so poor and got careless.
What was the thief going to do with my saddle? Sell it or use it? Anyway I have to ride my bicycle out of the saddle for a while…