cell phone jammer legal problems

Legal problems about mobile phone jammer, we have discussed a lot of, but is the legal problems about mobile phone jammers, there are different kinds of sound, what mobile phone jammers and illegal? There are different laws and regulations in different countries on this issue. Cell phone jammer are illegal in many countries and can be used legally only in special places. But there are still a lot of people buy and use of cell phone jammers, because now harassing phone calls and fraud phone theft of information such as things too much, people use mobile phone jammers is just in order to better protect their own safety.

Why can my mobile phone be used anywhere in Japan, but not overseas? I want to know if some people have overseas experience, or for the first time, there is a suspicion that the radio waves on the phone don't have the interference to draw radio waves from the outside. But in the real world, there have been a lot of unauthorized products, depending on the device and the production of a radio wave fault device in some areas.
http://www.jammer-buy.com/cell-phone-jammer/c-24.html