Critical Mass

An ostensibly-new police strategy was employed at the Ottawa Critical Mass of 2009-06-26...

The police car approached from behind and, from a speaker, the officer ordered the group to go single-file.

Then, the car veered forward and out into the oncoming traffic lane and then alongside the CM group, ostensibly repeating the order to go single file.

At one point, although unclear, due to some distance, the car seemed to edge dangerously sideways to force the group toward the curb and into the desired single file.