The effects of bugging an office, 12 years later, FBI bugger reflects on Phila incident.
A bug in your office could hurt you in many ways. Theft of information is one, but the revelation that the bugging took place can have other ramifications as well. The discovery of an FBI bug in the mayor’s office by the Philadelphia Police, may have cost the opponent his election- even though he had nothing to do with it at all.
If you suspect that listening devices may have been installed in your office or conference room, the inspection and any follow up investigation needs to be handled very discretely.
Mitch Blacher from NBC10 was able to interview J.J. Klaver, the FBI agent who planted the bugs.
Site of 2003 FBI bugging operation, office of Philadelphia Mayor John Street
Former FBI Agent Who ‘Bugged’ Mayor Street’s Office Speaks Out by Mitch Blacher,

If you see a coworker pointing an antenna like this at your smart phone you might have cause to worry.
IBM Selectric Typewriter 
This Instagram photo shows a listening device behind a plug socket in a wall
‘There will always be surprises’ was Ai Weiwei’s caption to this photo
A device concealed in an artificial rock in the southern Lebanese town of Bani Hayyan. According to the Lebanese Army, the device is an Israeli surveillance camera. (screen capture: Lebanese Armed Forces Facebook page) 