Others know your confidential business or professional trade secrets.

This is the most obvious indicator of covert surveillance activities. Often the loss of your secrets may not be readily apparent, so you must be vigilant in execution of your security program and of what your competitors are doing. When your competitors know things that are obviously private, or the media finds out about things they should not know, then it is reasonable to suspect that you are the subject of covert surveillance activities.

Secret meetings and bids seem to be less than secret.

Confidential meetings and business strategies are very popular targets for corporate spies. You would not like the plans for the corporate mergers and business strategies you are planning to become public knowledge?  Copies of your product designs would be useful to your competitors?  If your competitors knew how much you are bidding for a project they can underbid you and take away business.

People seem to know your activities when they shouldn't.

Does your spouse or significant other know what you are doing or where you have been and you have not told them beforehand? 

Your electronic devices have suddenly developed strange interference.

Many legitimate devices such as cordless telephones, wireless routers, etc work on the same frequencies as surveillance devices.  The frequencies include but are not limited to 900 Mhz, 1.2 Ghz, 2.4 Ghz, 5 Ghz.  If your electronic devices suddenly start to suffer the effects of interference it may be due to a surveillance device operating in close proximity.  A TSCM specialist can investigate.

You have been the victim of a burglary, but nothing was taken.

Professional eavesdroppers often break into a targets home or office, and very rarely leave direct evidence of the break-in; however, occupants of the premises will often "pickup on something not being right" such as the furniture being moved slightly.

Electrical wall plates appear to have been moved slightly or "jarred".

One of the most popular locations to hide eavesdropping devices is inside, or behind electrical outlets, switches, smoke alarms, and lighting fixtures. This requires that the wall plates be removed. Look for small amounts of debris located on the floor directly below the electrical outlet. Also, watch for slight variations in the color or appearance of the power outlets and/or light switches as these are often swapped out by an eavesdropper. Also note if any of the screws which hold the wall plate against the wall have been moved from their previous position.

A dime-sized discoloration has suddenly appeared on the wall or ceiling.

This is a tell tale sign that a pinhole microphone or small covert video camera has been recently installed.

One of your vendors, co-workers, or competitors just gave you any type of electronic device such as a desk radio, alarm clock, lamp, small TV, boom box, CD player, and so on.        

Many of these "gifts" are actually Trojan horses which contain eavesdropping devices. Be very suspicious of any kind of pen, marker, briefcase, calculator, "post-it" dispenser, power adapter, pager, cell phone, cordless phone, clock, radio, lamp, and so on that is given as a gift. That little gift the salesman left for you may be a serious hazard.

The smoke detector, clock, lamp, or exit sign in your office or home looks slightly crooked, has a small hole in the surface, or has a quasi reflective surface. 

These items are very popular concealment for covert eavesdropping devices. Often when these devices are installed at a target location they are rarely installed straight. Also watch out for things like this that "just appear", or when there is a slight change in their appearance.

Certain types of items have "just appeared" in your office of home, but nobody seems to know how they got there. 

Typical items to watch for and beware of are: clocks, exit signs, sprinkler heads, radios, picture frames, and lamps. Also be aware of items that are replaced without cause.  Many times an office or location is visited (or photographed) to determine which items can be replaced with a like item that contains a surveillance device.  Some companies will custom build a surveillance device into a specific item.  The Trojan can then be swapped with the original.

White dry-wall dust or debris is noticed on the floor next to the wall.

A sign that a pinhole microphone or video camera may have been installed nearby. It will appear as if someone has dropped a small amount of powdered sugar either on the floor or on the wall.

You notice small pieces of ceiling tiles or "grit" on the floor, or on the surface area of your desk.

Prime indicator that a ceiling tile has been moved around and that someone may have installed a hidden video camera or other eavesdropping device in your office or near your desk. Also watch for cracks or chips in the ceiling tiles. Amateur and poorly trained spies tend to crack or damage acoustical tiles. The ceiling tiles in any executive areas should never contain any cracks, nicks, gouges, or stains. Any ceiling tile that becomes damaged (for what ever reason) should be immediately replaced and the cause to the damage documented. In such cases it is also wise to have a TSCM specialist inspect the area around the chipped, broken, or damaged tile to determine if a hostile eavesdropping device may have been introduced.

Your door locks suddenly don't "feel right", they suddenly start to get "sticky", or they completely fail.

Prime evidence that the lock has been picked, manipulated, or bypassed. Try to always use biaxial locks with sidebars (such as ASSA or Medeco). Also, only use double sided deadbolts in all doors, and good quality window bars on all windows, and a good quality door bar on all doors not used as a primary entry doors. Watch for tool marks on door frames and areas around the deadbolt and strike plate.  These are signs that someone has tried to force the lock to gain entrance.  Another trick is to stuff the bolt hole with paper so that the bolt will not completely seat, making it easier to force the lock.

Furniture has been moved slightly, and no one knows why.

A very popular location for the installation of eavesdropping device is either behind, or inside furniture (couch, chair, lamp, etc).  People who live or work in a targeted area tend to notice when furnishings have been moved even a fraction of an inch. Pay close attention to the imprint which furniture makes on rugs and the position of lamp shades. Also watch the distance between furniture and the wall as eavesdroppers are usually in a hurry and may not put the furniture back in the right place.

Things "seem" to have been rummaged through, but nothing is missing (at least that you noticed).

A "less than professional spy" will often rummage through a targets home for hours, but very rarely will they do it in a neat and orderly fashion. The most common "rummaging" targets are the backs of desk drawers, the bottom of file cabinets, closets, and dresser drawers.