Many Canadian non-profit organizations are protesting the latest federal budget, here:
If you know of any organizations that use Drupal and would like to participate, you're welcome to use and/or recycle this simple D6 sandbox module (based on a similar module created for the US sopa campaign earlier this year).
or just use this command to grab it:
git clone --recursive --branch master http://git.drupal.org/sandbox/adixon/1611860.git blackoutspeakout
It's pretty plug and play, you just have to enable it and it'll "black out" the site with an appropriate replacement page for the day on June 4.