Facebook cares a lot about what its users say on its social network. By care I mean they want data they can use to serve tailored ads to Facebook users. Now it looks like Facebook also cares a lot about what users don't say. The company recently conducted a study to find out how often members censor themselves. They didn't read messages or log keystrokes. Instead Facebook considered a post or comment self-censored if it took more than 10 minutes to write and was at least five characters long. Turns out, of the 3.9 million members studied 71 percent censor themselves. Other key findings: posts are censored more frequently than comments. Males are more likely to censor their posts. And people are more likely to censor themselves when they're not sure who's reading their message. Based on what's in my newsfeed, I only wish that more people filtered their posts. And if Facebook moves ahead with plans to include video ads that automatically start to play, it's going to get even more frustrating to find posts that are worth a read and a response.