The definition from Wikipedia: The word is considered a pejorative term that describes "feel-good" measures, in support of an issue or social cause, that have little or no practical effect other than to make the person doing it feel satisfaction. The acts also tend to dilute awareness campaigns and require minimal personal effort from the slacktivist. Examples of activities labeled as "slacktivist" include signing internet petitions, the wearing of awareness ribbons or awareness bracelets with political messages, putting a ribbon magnet on a vehicle, joining a Facebook group, posting issue-oriented YouTube videos, altering one's personal data or avatar on social network services, or taking part in short-term boycotts such as Buy Nothing Day or Earth Hour.
I found this out when I was doing research about the whole deal this past weekend on Facebook where so many were encouraging people to change their profile pic to a cartoon character to, as many of their copy and pasted status updates implored, "raise awareness of child abuse". Because people are unaware, currently? Anyway, I thought the cartoon characters were cute. Then on Sunday evening a new message started appearing on people's status updates warning that it was in fact an insidious plot by those pesky pedophiles, and for authenticity, the copy/pasted messages said that the story had just been on 60 Minutes. (I had actually watched 60 Minutes, and there was nothing.)
The idea of what should be a charitable action being not only selfish but actually detrimental is kind of hilarious, though. And I have to admit this twinges me, too, as I have eagerly signed internet petitions and worn awareness ribbons and posted issue-oriented YouTube videos in the vague hopes of somehow being helpful. But how, really, does "raising awereness" help anything if it is an issue (like AIDS, or breast cancer, or child abuse, etc) that people are certain to be already aware of?
Dagnabbit, I kind of liked being a slacktivist.