She's wary of social media but sets up a Facebook account to track her 15-year-old son. He's been running with a bad crowd, and she just wants to see what's going on. When she asks to friend him, he ignores her request.

She finds his Twitter feed, @addled, and adds herself as a follower. He tweets about girls named Molly and, oddly, poetry. She likes one out of every three tweets and retweets some 140-character verse, though she has no followers. She follows some of the people her son follows and is half-shocked, half-intrigued by the casual danger they seem to get into: driving stoned, having unprotected sex. She types a few unsolicited comments, gets both rebuffed and applauded, and starts tweeting as @vigilantemom. She acquires a bunch of followers with hashtags like #useacondom and #donttakethattoke. They form the Vigilante Mom posse.

She gets onto Instagram and finds a cache of photos assembled by her son, having to do with a girlband called Molly Alone. She downloads three of the band's songs from iTunes and gets annoyed by some lyrics romanticizing blow jobs. She composes alternate lyrics describing what an icky taste, what a messy waste. She makes a short video with her cell phone, singing her lyrics in the kitchen and showing a little more skin than she should. She uploads it to YouTube, getting a boost from her Twitter followers, and the 45-second video gets 5,000 hits.

Meanwhile her son spends up to eight hours a day in his room, then heads out with his oversized iPhone sticking out of his cargo pants pocket like a flat extra limb. So she texts him, adding a heart emoji, and he actually texts her back, but it's one word: mom!

She emails him, asking if he'll be home for dinner. She gets an automated reply that he's away and unable to return her message until September. It's November 5.

She goes on Tumblr and stumbles out two hours later, amazed at what's available, from girls on molly to Molyvos to donkey sex. She was just looking to see whether her son had an account, but got sidetracked. As she thumbs through shots of MILFs, she catches a series of images that one of the vigilante moms has posted, GIFs of herself getting funky. She figures what the hell and does her own dance: three stills, including one up close and kinda graphic. That somehow gets reshuffled to a feed featuring Beyonca©, and suddenly her Twitter feed blows up, with links to music and even that stupid girlband, Molly Alone.

She posts on Facebook, this time opening up beyond vigilante moms to singing moms, dancing moms, strip momz, guys who like any and all of the above, and now she has more friend requests than she can handle. One of them is her son. She pauses when she sees the request, pondering her changed status, thinking about what it means to be a mother, wondering whether to confirm.