The logical reaction to this finally catching on with more than just a handful people here is as follows: DO NOT take your mobile phone to meetings where sensitive things are discussed! If you can, give the phone to a friend, partner or flatmate for the time you'll be out doing stuff so that they can carry it about somewhere you are not.

If it cannot be avoided to bring a phone to actions or preparation meetings, put it in another room or switch if off AND remove both the battery and sim-card!

All we need to fight back is our brain!
Turn the Computers on them!

Don't bother with them .. we never did in the past!!

Keep the phone in a small, well padded, sound proof bag and chuck the paranoia.

It turns it from a bug to a tracking device. I try and leave mine on but a distance away. What may seem being paranoid when you are facing a night or two in gaol seems like common sense when you are facing worse.

There is a scene in The Lives of Others where dissidents try to test whether they are being bugged, which leads to tragedy. Britain is more heavily bugged than anywhere at anytime in history. Do you know the MI5 symbol is the all seeing eye at the top of a pyramid ? Derivative black art.