Mayor BloombergMayors Against Illegal Guns, a gun control organization partly overseen by New York's Mayor Mike Bloomberg, is using footage from the Columbine High School shootings to get their point across. The organization counts more than 500 mayors from across the country as part of their group, which seeks to prevent the purchase and dissemination of illegally obtained guns by criminals. Their aim is to develop laws, practices, and policies that will allow Americans to own guns, but prevent criminals from possessing them illegally. Mayors who belong to the group come from a diverse range of locations , including Orlando, Florida; Portsmouth, VA; St. Paul, MN; and Vista, CA. More than $250,000 will be spent on ads to air on cable TV stations. The ads, which feature video shot by surveillance cameras at Columbine High School, started running yesterday in states including Colorado, Maine, Massachusetts and Virginia, in order to reach the senators of those states. The ads make the point that four of the guns used in those horrific shootings were purchased at gun shows, where background checks are not required when purchasing a firearm. Last year, more than $1.5 million was spent by New York City on detectives who went undercover at gun shows and bought weapons. The detectives even told the sellers that they wouldn’t pass a background check. Congress has not been able to push through laws requiring background checks for gun purchasers. A spokesman for the National Rifle Association (NRA) said that background checks at gun shows would take too long, and also hamper the rights of gun owners who purchased their weapons legally.