False rumors are able to spread throughout a large population before being debunked. Corrections, however, are only really able to spread to people who previously saw the rumor. Furthermore, many people who shared the rumor may be less likely to share the correction, since it makes them look gullible for sharing the unverified rumor in the first place. So it's much harder for a correction to spread virally.<p>If there were a system in place so that false rumors could be debunked in real-time, in-line (as opposed to using a separate retroactive correction), they would be less likely to spread as far. The closest thing I can think of would be something like Genius.