Friday’s report on the criminal history and Internet presence of a Suffolk man accused of making a bomb threat at King’s Fork High School turns out to present a lesson about impressions that is an important one for everyone to learn, whether they’re facing criminal scrutiny, a job interview or a first date.

In this era of hyper-sharing, when things don’t seem quite real to some folks until they’ve been shared on Facebook, Twitter, Instagram and various other social networks, there’s a tendency among many — especially the younger generations — to post all sorts of antisocial, incriminating, crass or otherwise questionable material on accounts that bear their names and photos.

It can seem so harmless, since clicking the screen closed or turning the telephone display off puts the content of those sites out of sight and out of mind. But the Internet is never really off, and despite the ease with which users can add things to their accounts, things posted online have a level of persistence that can make a tattoo seem like washable paint by comparison. It might seem easy to delete that photo from your Facebook profile, but scrubbing it from the Internet altogether — much less from your computer or telephone memory — is a far different matter.

A couple of rules of thumb are helpful in the matter:

4If you don’t want the world to see whatever you’re doing, don’t let someone photograph it.

4If you or someone else takes photos that might ever be considered incriminating, don’t put them online — anywhere — and don’t ever email or text them to anyone.

4Before posting photos of or a status about yourself, consider whether you’d want your grandmother to see the photos or read the status. The chances grow every day that she will, no matter how careful you are with your privacy settings. And if it’s not her, it could be a future employer, a potential mate or even the police.

And finally, a piece of advice — found on Facebook, of all places, and paraphrased here: Better to live in such a way that that you have no reason to worry what’s posted about you online. Then you’ll never have to spend the night fruitlessly scrubbing an online account that prosecutors have already mined and copied.