OK, I'm guilty. At least partly guilty.
I've jumped on the bandwagon of support for certain causes based upon a very superficial understand of the facts. I found this very telling and interesting infographic that helps build the story! http://www.onlyinfographic.com/2012/the-rise-of-the-slacktivist/
And Wikipedia adds to this story. Slacktivism (sometimes slactivism or slackervism) is a term formed out of the words slacker and activism. The word is usually 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 tend to require minimal personal effort from the slacktivist. The underlying assumption being promoted by the term is that these low cost efforts substitute for more substantive actions rather than supplementing them, although this assumption has not been borne out by research. 
Slacktivist activities include signing Internet petitions, joining a community organization without contributing to the organization's efforts, copying and pasting of Social Networkstatuses or messages or altering one's personal data or avatar on social network services. Research is beginning to explore the connection between the concept and modern activism/advocacy, as groups are increasingly using social media to facilitate civic engagement and collective action.
But is it all bad?
I'm not really sure...and I'm hoping that it's not. Could this "light" form of activism be the gateway for a higher level of responsibility? There are many pitfalls to engaging in a cause based more upon emotion than reason. But then again, I'm reminded of various protest movement that were driven from the heart. Movement that engaged with a visceral connection that moved millions. Vietnam, the civil rights movement, woman's suffrage, the peace movement of the 1960's are all part of activist movement that resonated, often times, from the emotional reality that "this is just right". The foreign policy implications of a war or the local protest impact on small businesses were lost of the "urgency of the moment". Today, that urgency is often expressed electronically. And the peace signs of yesterday are the Facebook and Twitter posts of today!
Tread lightly and think about what you're doing!
The simple reality is that people and movements need to do their home work. The rapid gain of popular support as seen in slacktivism comes with a significant risk. This mainstream popularity will also drive significant public scrutiny that could just as easily kill a cause as invent one. Simply put, nothing can crush an invalid or phony cause faster than social media. So, I'm hoping that there is a element of optimism in slackitvism and the social movements of tomorrow aren't compromised by lazy minds and lazy bodies.