It’s just 140 characters – how much damage could it do? Well, just ask Justine Sacco, Anthony Weiner or — most recently — Ted Cruz.

The quick, casual nature of Twitter makes it easy to spout off opinions or indictments without thinking about them — and those thoughts made permanent could come back to haunt college applicants.

Since teens are already more prone to impulsiveness than adults, their risk of tweeting something they’ll regret is higher than for the general population. They may put on a bold front to catch attention or get in with the popular crowd, participate in subtle cyberbullying, or align themselves with an inappropriate cause to gain favor with peers. It’s typical high school behavior, only on a very public scale.

As of late 2016, there were 317 million active users Twitter. And according to the Pew Research Center's Teens, Social Media & Technology Report, 33 percent of all American teens use Twitter, and they’re quite likely to have an open profile. Also, according to Pew Research:

• 64 percent of teens with Twitter accounts say that their tweets are public, while 24 percent say their tweets are private.
• 12 percent of teens with Twitter accounts say that they “don’t know” if their tweets are public or private.
• While boys and girls are equally likely to say their accounts are public, boys are significantly more likely than girls to say that they don’t know (21 percent of boys who have Twitter accounts report this, compared with 5 percent of girls).

As a high school counselor, do you have a responsibility to monitor specific students’ Twitter accounts relative to their goals? Maybe. Of course, you can’t oversee your entire school’s social media activity, but for students with whom you’re working closely — for example, to help them get into a competitive school or to stay out of legal trouble — it could be worth your while to see if there’s a public Twitter account associated with their name.

Now, what if that’s the extent of your knowledge? How can you help students make sure their Twitter presences are on the up-and-up if you don’t know what to look for? Here’s a quick guide to the basics of Twitter and what to look for in student accounts:

Tweet: A tweet will be visible to anyone who views your (public) profile. Students should not use foul language, racial slurs or engage in cyberbullying in their tweets.

Like: Users can “like” a tweet to show they find it helpful, inspiring, important or funny. Even if they’re not expressing a sentiment themselves, a Twitter “like” usually implies the same thing.

Retweet: If you see someone else’s tweet and find it really helpful, inspiring, important or funny, retweet it. You can retweet with or without commentary. The retweet will show up on your own feed, putting the original content and your annotation, should you choose to add one, in front of all your followers. The same logic as above applies: If a student retweets what someone else is saying, unless they explicitly comment otherwise, they’re showing alignment by default.

Follow: How many followers a student has is often a popularity contest. It’s also correlated with the likelihood of someone seeing the things they’re tweeting about.

Hashtag: A hashtag is the pound symbol followed by a word or phrase, and it brings together everyone who’s talking about a particular topic. Click a hashtag to see all the tweets featuring that topic.

Converse: If you want to interact directly with someone else via Twitter, mention them by name using the @ symbol. This message will be public, so everyone else can see it too.

DM: When you want to interact with someone privately, you can send them a Direct Message (or DM) that won’t show up in anyone else’s Twitter feed.

Life of a tweet: Tweets live forever, so students need to be careful with what they say. You can delete a tweet after the fact, but anyone can see it while it’s still live.

It often makes sense to recommend students just make their Twitter accounts private in times of potential scrutiny, but not always. In certain cases (for instance, if a student is angling to get accepted into a competitive school based on their knowledge of, passion for or involvement in a cause), Twitter can help bolster their position.

It’s more than 140 characters — it’s a powerful reputation-builder. Make sure your students are using it wisely.