If you “like” something, does that mean you care about it?


It’s an important distinction in an age when you can accumulate social currency on Facebook or Twitter just by hitting the “like” or “favorite” button.


The ongoing referendum on the Web often seems more like a kind of collective digital graffiti than a measure of engagement: I saw this thing, it spoke to me for at least one second, and here is my mark to prove it.


But it gets more complicated when the subjects are more complicated. Hitting the favorite button on the first episode of “Mad Men” is a remarkably different gesture than expressing digital solidarity with kidnapped children in Africa, but it all sort of looks the same at the keyboard.


In the friction-free atmosphere of the Internet, it costs nothing more than a flick of the mouse to register concern about the casualties of far-flung conflicts. Certainly some people are taking up the causes that come out of the Web’s fire hose, but others are most likely doing no more than burnishing their digital avatars.


In February, the digiterati went bonkers after the Susan G. Komen foundation (shorthanded as #Komen on Twitter) announced it was cutting off financing for Planned Parenthood. And then #KONY2012 started popping up in my Twitter feed and I, along with 100 million others, watched a video about the indicted Ugandan war criminal Joseph Kony.


After weeks of remaining under the radar, #TrayvonMartin began to surface as well, with many suggesting that the people who got so frantic about the victimization of young black males on another continent needed to look closer to home, at the death of an unarmed black teenager in Florida.


As a reporter, I don’t sign up for various causes, but as someone who lives — far too much — in the world of social media, I can feel the pull of digital activism. And I have to admit I’m starting to experience a kind of “favoriting” fatigue — meaning that the digital causes of the day or week are all starting to blend together. Another week, another hashtag, and with it, a question about what is actually being accomplished.


I ended up thinking a lot about the power and limits of digital activism earlier this month when I was in Moscow during the Russian presidential vote. I spent election night with Aleksei Navalny, a Russian blogger who had become a tip of the spear in the social media campaign against the current government. On that night, camera crews from around the world swirled around him and it seemed as if anything was possible.


But by the next day, it was clear that Vladimir V. Putin would retain his grip on power, and Mr. Navalny ended up posting on Twitter from police custody when he was arrested after an opposition rally. Social media activism may prove to be a durable force in Russian politics, but in these early days it is no match for offline might.


Evgeny Morozov, the author of “The Net Delusion: The Dark Side of Internet Freedom,” is not entirely dismissive of the Web as a political organizing tool, but is skeptical of the motives, and power, of digital activism.


“My hunch is that people often affiliate with causes online for selfish and narcissistic purposes,” he said. “Sometimes, it may be as simple as trying to impress their online friends, and once you have fashioned that identity, there is very little reason to actually do anything else.”


Which brings us to the online campaign denouncing the fact that “Bully,” a movie about child-on-child harassment and violence to be released Friday, has received an R rating from the Motion Picture Association of America’s ratings board.


I have watched the evocative trailer for the movie and met the director, Lee Hirsch. And as a parent of a 15-year-old, I have skin in the game.


On Thursday, word came that David Boies and Ted Olson, the attorneys who were on the opposite sides of the Bush v. Gore Supreme Court case, had joined the effort to persuade the motion picture association to change the film’s R rating to PG-13, so that the young people most affected by the issue could actually see the movie. Celebrities and politicians, everyone from Drew Brees to Justin Bieber, have weighed in, as have more than 460,000 people who’ve signed an online petition demanding that the rating be changed.


The petition was started by a teenager, Katy Butler, who was bullied for being a lesbian, and has blown up huge on Twitter and elsewhere.


“We were absolutely disappointed with the rating,” Mr. Hirsch told me Friday. “This film has been heralded and welcomed by all kinds of education groups, and multiple school districts were planning to take their students en masse.”


Mr. Hirsch said the petition came out of nowhere. “I got an e-mail the day after it started and I have watched it rising since,” he said.