I just found some news about electric fencing (i wasn't even looking, two thumbs up for me! ) here it is:

Radio-fences for dogs Canada Some dogs are just too crafty to be penned in by a radio-fence. I know of two beagles who patiently chewed each other's collar off and then went on the lam, leaving their tattered prison duds behind. Another dog figured out how to beat the radio-fence, by running as fast as he could until he was out of its range and influence. In theory, radio-fences sound good; however, just don't expect them to work if your dogs are escape geniuses. [Canada.com] Related: Radio Fences

That's pretty funny! Dogs are sure smart!