In the last several days, there have been a number of published stories about the Hells Angels protesting the legalization of cannabis in front of Canada's Parliament buildings.
At the time of writing, the story has been shared more than 100,000 times on Facebook and Twitter. The supposed reason for this protest: the organized crime group is worried about falling profits in the face of a legal, regulated market.
The Hells Angels may indeed be concerned about how legalization will impact its business operations, but there's no evidence that an organized protest took place.
The original source of the story seems to be World News Daily Report, a site with a serious name and not-so-serious stories. Other "well researched" stories on the site include one about an activist spending a year in a freezer to protest global warming, and another about a hairy man killed by hunters who believed he was a sasquatch.