We love Rainn Wilson, so we want him to play The Riddler in the next Batman film. We're going to use the Internet to make it into a reality. We're just going to pretend that it's already happening, and try to convince the rest of the world that it's happening too. If enough people believe it, they'll have to let him play The Riddler.
Spread the news that Rainn Wilson got the role as The Riddler using Twitter, Tumblr, and Facebook. Use hashtags (such as #RainnRiddler, #Riddler, #RainnWilsonRiddler, etc.) to help spread the message. To provide authenticity, link to this fake story we mocked up earlier.
With any luck, the message will start to spread itself. Everyone needs to stay on message though, nobody can reveal that it's all a carefully orchestrated ploy to make Rainn Wilson the next Riddler. We can make this happen. The Internet has unlimited power.