Is your cell phone bugged
Vortex (a US company) has produced an online Video, which they say is "to explain this issue in a more demonstrative and somewhat less technical manner..."
It raises some quizzical issues. This is not my attempt to be dismissive of what they are saying, but I could not help but think it does rely upon the subjectivity of each mobile phone user to perhaps determine if their battery runs down too quickly or the handset gets hot when not in use that information is being extracted from it.
The video authors do stress that any such use of monitoring mobile phones is not targetted at the general public, but those under surveillance. But that in itself may not stop the general public thinking something maybe up if they find the events occurring that have been suggested .
Whilst videos like this can be informative, they can introduce feelings of worry or paranoia to those who maybe vulnerable to such feelings. Perhaps it might assist, if a mobile phone user thinks this is happening to first rule out common events that the mobile phone may be exposed to:
A) had been left in direct sunlight
B) left close to a radiator or devices that emit heat generally in areas (kettles, photocopiers, computers/laptops etc)
C) that the user hasn't just taken the mobile phone out of the coat pocket (obvious I know, but worth saying anyway)
D) reduction in battery power occurs because of resource greedy applications running on the mobile phone
E) does update to the network and in areas were poor radio coverage pockets occur or where the mobile is located at the radio boundary of a Mast's coverage, updating to the network does increase energy consumption (drawn from the battery)
F) where a mobile phone is swtiched OFF and battery still runs low, it could be a fault of a bleed from the battery or that the mobile's firmware is faulty regarding e.g. the clock and draws more power from the battery at a higher rate
G) using broadband might require the ISP or application service to 'ping' the mobile to ensure the account is still connected, which might be a separate event from updating to the network regarding the subscriber IMSI-attach status for example
These are just some observations that might help, but if a mobile user is still concerned, the video does demonstrate a detection method using speakers. But even that may produce a false-positive result. There is of course another method that may eliminate this matter which the video suggests is to remove the mobile phone's battery. OK, but that doesn't take account of when the mobile is switched ON and in the idle mode. If the mobile user still feels uncomfortable, then change to a different or new mobile phone.