Originally Posted by
soitgoes
Be aware that, as far as I know, using such blockers is illegal in the USA. The FCC does actually investigate reports of blocker use (although mostly referring to fixed locations).
It is illegal to sell, purchase or use jammers here in the United States ($10K fine) but you can still get them from Asian web sites. They can be sold in the UK but it is illegal for civilians to own or use them.