Many customers at a small town grocery store in Alberta had trouble unlocking their cars, while others had their car alarms going off mysteriously, since early January. According to the CBC [www.cbc.ca], after trial-and-error of turning off electricity to nearby buildings and calling in the federal government for assistance, the source of the interference has been traced back to "faulty consumer electronic equipment stuck in transmit mode".
The story of the original mystery can be found here [www.cbc.ca].