Not sure where to post this so I'm putting it here: http://www.torontosun.com/2014/08/18/elections-canada-eyeing-liberals-ov...
Elections Canada is investigating an incident that occured in the 2013 by-election in Bourassa in which Liberal supporters were videotapped removing NDP signs. I'll note that in another NDP-Liberal by-election battle, numerous NDP signs were also removed.
This story by the Toronto SUN is the only mention of this investigation I have seen in the media. For comparison, when it was announced EC was investigating the NDP's satellite offices, the media was all over it.