The ease of participating in a social or political activity online is inversely proportional to its effectiveness.
In other words, the easier an exercise in online activism, the more worthless it is. High ease = low effectiveness (thanks to Jamy for the correction).
Obviously, this is just a restatement of any number of old adages that say you get out of something what you put into it. But I still see far too many people online who delude themselves into thinking that they've done something worthwhile just because they clicked "OK" somewhere.
- Signing an online petition or pledge: Ease: Ultralow. Usefulness: Ultraworthless
- Sending e-mail to an elected official: Ease: Low. Usefulness: Low (worthless if you're not actually a constituent.)
- Joining a Facebook group: Ease: Low. Usefulness: Low (unless it's in support of a tangible result, like a rally, or would potentially get you killed by the Mafia or guerrillas, or would otherwise require, you know, actual time or effort).
- Participating in political forums: Ease: Low. Usefulness: Almost universally worthless -- because of the polarized, self-selecting, self-segregating nature of most online political communities, at best, you're preaching to the converted; at worst, you're engaging in yet another worthless online flamewar, convincing no one and simply reinforcing each other's stereotyped views.
- Political or advocacy blogging: Ease: Varies. Usefulness: Depends -- Are you creating anything original or simply rehashing other people's punditry?
- Using online activities to organize and mobilize offline activities: Ease: Varies. Usefulness: Well now, this is where things get interesting.
The trick, of course, is trying to figure out how to leverage all this online stuff into things that actually matter.