More than 13,000 people have joined a Facebook group that helps Canadian voters cooperate with the aim of defeating Stephen Harper and the Conservatives. The group, called Anti-Harper Vote Swap Canada, along with a related Facebook application, encourages people concerned about the prospect of a Conservative majority to vote strategically in the federal election on Tuesday (October 14).

People have until midnight tonight (October 9), to register to swap their votes.

Just how does vote-swapping work? The group offers this example:

Let’s pretend I’m an NDP supporter in the riding of Winnipeg South. Seeing as the Tories only managed to beat the Liberals by less than 150 votes in the 2006 election, the Liberals almost surely have the best chance of winning. I use the “anti-Harper Vote Swap” facebook application to indicate that I’m an NDP supporter who is willing to vote for anyone but the Conservatives. Even if you don’t know the latest polling data in your riding, we can help. We will then match you up with another member of the group (in this example, a Liberal in a strong NDP riding who is willing to swap). Assuming we find you a match, you’ll receive a message a few days before the election letting you know that your vote can be swapped.

CBC News reported September 17 that Elections Canada has determined that on-line vote-swapping is legal, as long as no money changes hands.