Darren
Mine would do nothing. Firstly it's attached to a 4 way manifold by a length of CVT tubing and you would have to pull off this. Secondly it has a regulator attached, which is normally turned off when not in use, so even if you depressed the handle nothing would come out. So I suppose at the most it would waste someones time, when they could be running for their life.
This is not a problem for me, both myself and my partner know that this bottle is useless for fighting fires and we're the only two people who live there. Secondly I plan to make a small cabinet to conceal the bottle, out-of-site out-of-mind, so no-one would accidentally grab it becuase they wouldn't even know it's there(although this is not the reason for the cabinet, I just want to make the whole brew fridge area look tidier).
We also have a working fire extinguisher in a much more prominent and accesible position, which you would naturally reach for first.
Cheers
MAH