In a post describing what he learned from mapping the riots in the U.K., James Cridland notes the amount of misinformation that spread on Twitter. He decided that he wouldn’t map an outbreak of violence unless it had been reported by an established news outlet or multiple people in different ways. Trouble was, media weren’t that reliable either. Another surprising lesson was that “many people don’t know what a reliable source is,” he wrote, noting that people sent him video that purported to be taken in one place when it was from another and that they simply passed on unverified information from friends. “I discovered it was surprisingly easy to check the veracity of claims being made on Twitter by using the Internet to check and cross-reference, rather than blindly retweet.” || Related: 5 ways journalists used online tools to report on London riots. || Earlier: U.K. photographer explains how she captured dramatic photo during riots.