Of course, back when me an thee were cracking villains skulls life was much simpler. RIPA and IPA make directed surveilance, test purchasing, etc, activities that require prior authorisation by a panel independent of the police, and that takes days (there are exemptions for serious threat to life and limb, etc, where the Feds can act with only a supernintendos authorisation).
Unfortunately, an activity such as this falls under that category and the dibble cannot lawfully become directly involvdd in advance, or encourage the victim to do so either (although they can't discourage them from doing it, they're private citizens and can do what they want with this...unlike the officers).
This is in much the same was that they can no longer park up in an unmarked car outside a pub and catch likely looking wino's as they drive off - thats directed surveillance, and requires authorising for each and every single subject they deliberately observe (if they genuinely just happen to be driving past themselves and spot the driver then thats a different matter). That used to be good Saturday night pickings for me, and probably you too Stevie, but that got knocked on the head in the early 00's thanks to RIPA.
So while I am firmly of the belief the Met should be disestablished, decapitated of its senior leadership, middle management removed, and reformed as an all new organisation in the manner of the RUC/PSNI, I do have some sympathy with their position here. This is directed surveillance and the dibble cannot lawfully become involved at the drop of a hat - the authority has to come from an independent panel outside of the police and takes days at the best, weeks being more likely. Of course, if the victim does retrieve their bike then the dibble can become involved in slow time after the event, but they cannot lawfully go and knock on the door with the victim, or hide behind a hedge in the front garden ready to leap out with handcuffs at the ready. There must be a distinct separation in both time and space before the dibble can become involve in such an operation without RIPA or IPA authority.
It ain't the 70s, or even the 90's, any more, cant have the police snooping about because people complain about invasion or privacy, hence these laws. Of course, that means when people suddenly do want the police to snoop about they suddenly find that they cannot do so any more.