I got into an argument on twitter about the efficacy of these kind of things. A charitable paraphrase of the tweet that I took umbrage with is essentially: "If I don't do bad things, and I don't know people who are doing bad things, I can't effect change"
Given that I got into an argument, you can understand I think this to be a terrible notion. There's huge numbers of ways you can effect change, and generally help causes even if you aren't part of the problem, or don't know people who are part of the problem.
A common complaint made when issues come up on twitter is that "Twitter won't change anything". While I think that history has started to show us that this isn't entirely true, a thought occurs to me:
If you agree with my thesis on an issue, criticize the crap out my efforts on said issue... but if you really want to change my mind, show me up. Do better than I am. Be more involved than I am, do more than I am, donate more than I am, fundraise more than I am.
I would much rather have you acknowledge that something can be done, and show me how to do it better, than complain that nothing can be done, and that my efforts are wasted and pointless.