If you've ever taken a ride on public transportation in Philadelphia, you know it can get a little noisy. Cell phone chatter fills the air on many of the city's buses, which can make for an unpleasant ride for some riders.

One man, determined to stop the cell phone noise, was caught jamming people's cell phone transmissions on the public bus commute. The local news station, NBC10, was able to track down the jammer along with some of the riders he's prevented from talking on the phone.

He's blatantly holding this device that looks like a walkie-talkie with four very thick antennae, said a woman who rides the bus with the Philadelphia cell-phone jammer. I started to watch him and any time somebody started talking on the phone, he would start pressing the button on the side of the device.

Bus-riders are outraged that the man has gone to this extent to prevent cell-phone chatter. The NBC10 news team confronted the Philadelphia cell phone jammer in person. They told him it was against the law.

It is my understanding it is more of a gray area, the Philadelphia cell-phone jammer told NBC10. It is my understanding that it's illegal to, you know, stop a television signal, a radio signal. You know, it's my understanding according to the FCC that it's not illegal to disrupt a cell phone signal.

He was wrong. NBC10 looked into the matter and cell phone jammers are illegal according to FCC regulations. The reason is because cell phone jammers could prohibit emergency vehicles from communicating with each other. It can also disrupt police communication and jammers may prohibit someone from reaching emergency services if they're used incorrectly.

The Philadelphia cell phone jammer doesn't seem to mind. He even says on camera that he's proud of what he's doing.

What is Cell Phone Jamming?

A cell phone jammer is a small device that looks like a walkie-talkie. It is used to prevent cell phones from receiving signals from base stations.

Cell phone jammers block cell phone operations by sending radio waves along the same frequencies that cellular phones use. The radio waves cause interference between the cell phone and its ability to communicate with cell phone towers.

Cell phone jammers come in a variety of sizes, can affect large or small radiuses, and can target a variety of cell phone bands (frequencies used to communicate with towers). Jammers either disrupt phone-to-tower frequencies or tower-to-phone frequencies. The latter is typically more effective.