Buggy hardware?

Several years ago, when I worked in a microelectronics research group, I received a panicked phone call from a person at one of the government's operations centers.

"My phone's been bugged," the caller said. "By the Russians." It turned out that he wanted me to come over to his office and find the bug that he thought was in his phone.

The caller sounded rather confused, so I didn't take him too seriously. I wondered why he thought the Russians had bugged his phone.  If my phone was bugged, I doubt that I'd know who bugged it. And even if you did manage to find a Russian bug, it probably wouldn't be labeled "Proudly made in the USSR" or something similar. People who bug phones probably like some degree of anonymity, after all.

The caller then explained how his phone would act strangely a few times every day. It would ring, but there would be no incoming call. The phone's buttons would light up by themselves and odd messages would scroll across its LCD display.

This sounded more than a bit like the power-on self-test for the caller's phone, so I suggested that he might be kicking the phone's power cord under his desk. I thought that this might have been causing his phone to lose power briefly and then start its self-test when power was restored by being bumped again.

The caller didn't like this idea at all. He was still convinced that his phone had been bugged by the Russians. I eventually asked him to keep an eye on the power cord for his phone and to call back the next day if the strange behavior of his phone wasn't connected with the power cord getting kicked.

He never called back.