He refused to dress up to meet the neocon, flagophile PM of Canada. The man is a wholly owned subsidiary of the US, of course, and therefore disloyal to his country.
UPDATE from Peter Lipa: "I had a good chuckle when I read the article about Justin Bieber not ‘dressing up’ for the PM of Canada. The reality of it is that the photo op is for the PM — not Bieber. Bieber’s not picking up fans because of a picture next to some Canadian politician. It’s the other way around. And, with the way the ‘stars’ are dressing today, do they really expect us to believe that Bieber dressed down for this occasion?? I’m sure that his stylist spent the morning figuring out what Justin would wear. It is to laugh! PS: I always enjoy LRC."