On June 21, 2012, a number of Occupy Boston activists were denied entry to Canada. One of the activists wrote the following tweets after being turned away from the border:

It's unclear whether Canadian authorities received any information from their US counterparts that assisted them in determining whether or not to admit these people into the country, though we know that US and Canadian officials share "real time" intelligence information at the border. 

Have you heard other stories of political interrogations or refusals at the US/Canada border? Tweet at us: @ACLU_Mass.

UPDATE: Apparently digital privacy activist Jake Appelbaum and pioneering independent journalist Amy Goodman have also encountered their own troubles at the Canadian border. (h/t @marymad)