We just had one installed in Beulah Road here in Thornton Heath. Needless to say one or more of the local Heathens has already tried to break the lock.
My wife’s pub bike is locked up outside with a massive chain to my Moto Guzzi plus an additional two D-locks.
Yes, sadly those bike hangers just aren't secure enough, so they're easy pickings for bike thieves.
(Didn't realise they had them in SW15 - I recognised that road straight away...)