Next here tonight, party patrol, police have found a new way in essence to spy on wild teen jj aj parties and stop them. Teenagers facing a surprise and a very serious guest. Abc's gio benitez.... See More
Next here tonight, party patrol, police have found a new way in essence to spy on wild teen jj aj parties and stop them. Teenagers facing a surprise and a very serious guest. Abc's gio benitez. Reporter: Teen throwing wild parties is nothing new, but nowadays fueled by facebook and turbo charged by twitter, they're easier to throw and getting wilder than ever. Take this one in a boston subu suburb. They barged into their house while their family was on vacation antsdz announced a party on facebook. 100 teens later, $45,000 in damage. They urinated in every single drawer in my house. Reporter: Thousands of miles away in los angeles, authorities are fighting back with a specialized unit, the first and only one of its kind, dedicated to tracking teen parties in realtime by monitoring special media. The lieutenant runs this unprecedented team and you're using search terms. Kick back tonight. It looks like I believe, we have six parties. Reporter: Tonight, the unit rolls out and we're along for the ride. At 10:52, they arrive. Party disperse, leaving a trail of evidence. Basically fill the balloons with the gas and then the kids inhale the gas out of balloons. Reporter: Mom knows there's party but -- they're having a party -- no, no, no. Reporter: Parents didn't want us to show their faces. He showed me the flyer. It showed that tank was going to be here and the beer. Reporter: It even surprised the kids. It was on the internet? Reporter: One party crashed. But the night is young. Gio benitez, abc news, los angeles.
This transcript has been automatically generated and may not be 100% accurate.