Signs that a phone is tapped include strange sounds on the line, splices in the phone wires, interference in other electronic devices, random debris, furniture and other items unaccountably out of place, repair trucks spending extended periods of time nearby and break-ins during which nothing is taken. Other indicators of possible tapping and spy software include warm battery temperature, unusual text messages and high data usage. Another indication is when confidential information spoken about over the phone becomes public.
Sounds such as unusual static, scratching, volume changes, breathing or clicking may indicate a phone is bugged, although professional wiretappers are generally able to avoid these obvious signs. A phone emitting noise when it is hung up or ringing when no one is on the other line may be tapped. Some eavesdropping devices use frequencies that disrupt the normal operation of radios and televisions. Unfamiliar wires coming out of a phone or splices in the middle of the wires may indicate a phone has been bugged.
Eavesdroppers sometimes break into a home or office to install equipment. Although they disturb as little as possible, furniture may be slightly out of place or the phone may have moved from its position. Sometimes wiretappers pretend to be telephone repair crew to plant eavesdropping devices. Taps to landlines can also be initiated outside by splicing into phone wires. Homeowners who suspect phone tapping should check with utilities companies when service trucks spend long periods of time parked outside or service crews make unscheduled visits.
Clicking sounds, static or distant voices over a phone connection could be indicators of tapping. These are not normal on digital phone networks, states BullGuard. Also, long shut down times can be indicative of spy software, as smartphones must finish all processing tasks before they can turn off. If a data transfer is in transmission, it must also finish before the smart phone can turn off.