Mobile phone conversations on buses, at train stations and in restaurants can be distracting to other people and they can even create public safety concerns for law enforcement, but is it ever OK for a third-party to block those calls?

The issue has been getting extra attention of late amid a Philadelphia man's use of a mobile phone jammer on a bus and the Federal Communications Commission's request for public comments about whether law enforcement should be able to shut down mobile networks in certain situations.

According to the Los Angeles Times, there's a good reason people get disturbed by the chatter around them.

Researchers at Cornell University found that hearing half of someone's conversation distracts people and can actually lower their cognitive ability.

Apparently, people have a hard time ignoring what the researchers called a "halfalogue." They said it's because people can't predict the speech pattern of a halfalogue like they can with a monologue or two-way conversation.

As vexing as overheard cell conversations can be, what the Philadelphia man was doing is technically against the law. He was caught by NBC investigators who found that he was using a mobile phone jammer to disrupt the phone calls of fellow riders whose cell phone chatter he found irritating and rude.

"We remind and warn consumers that it is a violation of federal law to use a cell jammer or similar devices that intentionally block, jam, or interfere with authorized radio communications such as cell phones, police radar, GPS, and Wi-Fi," states the FCC on its website.

Once the annoyed bus rider wielding the mobile phone jammer learned what he was doing was illegal, he said he would stop.

At the same time, apparently the issue of whether a third-party has the right to block cellular transmissions isn't actually cut and dried.

In fact, the FCC is currently asking for public comments about whether it's ever appropriate for law enforcement agencies to shut down mobile networks in the name of public safety, as San Francisco's Bay Area Rapid Transit did last August when it tried to prevent a protest.

In the FCC's request for comments [PDF], the agency stated that about 70 percent of 911 emergency calls in the U.S. now come from mobile phones but some law enforcement agencies are concerned that mobile phones can be used to do nefarious things such as detonate explosives or organize violent flash mobs.

"Our democracy, our society, and our safety all require communications networks that are available and open," FCC Chairman Julius Genachowski said in a statement. "Any interruption of wireless services raises serious legal and policy issues, and must meet a very high bar."

You have until April 30 to weigh in on the issue. To do so using the Internet, visit the FCC's Electronic Comment Filing System.

[See more: Researchers Develop a Speech-Jamming Gun That Will Shut You Up]

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