This is very much what I would call doing your part. From Salon.com:
Since conspiracy theories have already arisen surrounding the Boston Marathon bombing, one man in California is doing what he can to head them off by registering the domain name bostonmarathonconspiracy.com. If you visit the site, you get this message:
I BOUGHT THIS DOMAIN TO KEEP SOME
CONSPIRACY THEORY KOOK FROM OWNING IT.
PLEASE KEEP THE VICTIMS OF THIS EVENT
AND THEIR FAMILIES IN YOUR THOUGHTS.
It’s a simple, small, but powerful gesture of goodwill from a stranger 3,000 miles away from the scene. Jaimie Muehlhausen, the man behind the site, explained in an email to Salon that he wanted to do something after seeing so many other tragic events become fodder for theorists:
Sadly, one of my first thoughts was that it would only be a matter of hours before a certain group of people would begin to say it was a government conspiracy; an act of terror on our own people for political gain. It’s sickening, but take a look at the massive numbers of 9/11 conspiracy nuts…people who think Bush and the gang took down the twin towers and ended the lives of nearly 3000 people so we could go to war. The heartless and sick Sandy Hook conspiracy theorists who think the Obama administration killed kindergartners to bolster the gun control debate. And there are plenty of others. Well, I was wrong. It didn’t take hours…it took minutes.
He didn’t post his name on the site, but didn’t hide it either from people who know how to look up such things, and feared he would be inundated by theorists. Instead, he said, “I have been encouraged by the number of emails from people literally all over the world who took the time to dig into domain records, figure out that I owned the domain, and send me a message of thanks for making sure the irrational assholes don’t win this one.”
Of course the theorists will will find another domain to use, “but this one is the most obvious name and it’s now unavailable for their bullshit,” he added.