There are a couple of principles to ensure an activity drive like this is successful:
You need a significant number of contributors acting under agreed upon guidelines. The contributors will give you reach and the guidelines prevent singular actors from ruining momentum by taking counter productive actions with good intentions.
You need lead-up time to gather contributors and establish guidelines. In this case you would probably want some Reddit mods sympathetic to your cause so that it doesn't sound like the initiative is from a purely external group.
You need to leverage bandwagon effects. In this case those Reddit mods are critical to giving the impression that there is already momentum in this direction.
You need a well formatted landing page to establish initial impressions. A lot of folks will click on exactly one link before giving up on an effort. You need to make that link count.
I'm working on compiling guides and establishing a community to organize initiatives like this over at !digitalcommunitybuilding. The project is in very early stages but the hope is to ensure your digital activism is actually effective.
All that said I would strongly recommend against this approach unless you can make a BIG push and that takes time to organize and a lot of one-on-one conversation.