I completely agree with Judy Rebick on this. 

Here's another recent Canadian example:

In the midst of the peaceful blockades in 2007 and 2008 by Algonquins and their supporters against uranium mining in eastern Ontario some nob(s) thought it would be cool to plant a firebomb at the office of Frontenac Ventures Corp., the mining company.  This childish "action" was universally condemned by all those who were doing the hard work on the blockades and other protest and legal actions to stop mining.  It is difficult to imagine any action which would be more effective in helping the mining industry to undermine the non-violent protest movement than planting a bomb.  The net result is to frighten many people away from the protests and allow the mining industry to depict themselves as the poor victims of violent, destructive extremists.  Not to mention giving the OPP a rationale that they wouldn't otherwise have had to wiretap activists' phones and conduct other forms of aggressive surveillance.  Certainly made me wonder if maybe the bomb was planted by agents provocateurs for the industry.