I think the thing which potentially pushes this over into criminal harassment territory is the bit where they encourage everyone to contact the business (via Facebook, etc.) to tell them their business sucks.
That would seem to be just about covered (with some pulling and straining admittedly) by s. 264 (2) (b) of the Canada Criminal Code:
(b) repeatedly communicating with, either directly or indirectly, the other person or anyone known to them
In other words telling all Hells Angels not to go the hotel and that it sucks and that they should tell everyone they know about it - legal.
Getting them all to contact the hotel and say “You suck”, not. Maybe. It’s pretty thin, isn’t it.
Although as it turns out this is another instance where Cory’s summary does not really reflect the article’s contents in all particulars…
The linked article does not contain any police officer saying specifically that this could be criminal harassment.
It does contain this:
The OPP’s Renton said while boycotting a business online may not be a crime, the reviews themselves can be.
“If they feel there are actions within those reviews that are criminal in nature, you know, whether they feel they are threatened or intimidated they can always contact the police.”
which is rather more general and pretty much what you’d expect the police to say 
