Screen shot of the Yik Yak app on Apple's App Store Screen shot of the Yik Yak app on Apple’s App Store.

Kids say awful and hurtful things about other kids all the time, of course. No need to repeat them here.

But there’s an app called Yik Yak that does repeat them, and spreads them, by enabling users to disseminate whatever they say anonymously to all Yik Yak user in a certain range, like in and around a high school.

Schools and authorities across the country are starting to move against Yik Yak.

“Some students have compared it to a virtual bathroom wall where users post vitriol and hate” reports Chicago’s WLS Eyewitness News.

Complaints got so bad in Chicago, in the schools,  that the company reportedly disabled its use there last week.

Yik Yak messages resulted in the lockdown of a high school in San Clemente, California, according to the Los Angeles Times:

Authorities were investigating each of the incidents. “It’s safe to say we’ll do whatever it takes to find out who’s behind this,” Orange County Sheriff’s Department Lt. Jeff Hallock told The Times.

A CBS affiliate in Massachusetts reported last week that  Marblehead High School was evacuated twice after someone posted threats on Yik Yak. Police have gotten involved in a similar case in Mobile, Alabama, where two teens were arrested for making threats about a school shooting.

The lesson in Mobile that could scare off some users was that the posts are not as anonymous as kids think. Mobile’s Fox10 TV reports:

“As soon as we became aware of the post, we went into action. We contacted the marketing director for the app and we began downloading and getting information sent to us about where these posts are coming from,” said Mobile County District Attorney Ashley Rich.

She said “students and people that use this app need to understand we know exactly where they are when they make that post.”

According to TechCrunch:

The startup was launched by two Furman University students, Tyler Droll and Brooks Buffington, aiming to connect people through anonymous, location-based posts. Within a five-mile radius, the poster can choose to share with the closest 100, 250, or 500 Yik Yak users. For $.99, users can share with 1,000 people, 2,500 for $1.99, and 10,000 for $5.

“Anonymity is a beautiful thing,” says a post on the Yik Yak web site. “”Anonymity is powerful, for better or for worse.” says blog post on the Yik-Yak web site.

There’s no “for better” in this case, as far as a lot of schools are concerned.