Jofi Joseph was a smart guy — up to a point. He rose smoothly through the foreign affairs establishment, boosted by a fancy fellowship and political connections. He ended up a staff member on the National Security Council.

But he led a second life on Twitter, using the handle @NatSecWonk to post snide comments about national security leaders. His droppings included such juvenile sexism as, “What’s with the dominatrix-like black suit (national security adviser) Susan Rice is wearing at this announcement?” And sophomoric snark: “When was the last time (deputy national security adviser) Ben Rhodes said something not painfully banal and obvious?”

Joseph’s Twitter alias provided only limited cover. After all, he was tweeting about things only insiders would know. He was eventually outed and fired.

As Twitter prepares to issue company stock to the public, investors are trying to size up its future in the social media universe. The microblogging site has a critical flaw anchoring its prospects. Unlike Facebook — which requires members to submit their real names and email addresses when joining — Twitter lets anonymous louts romp through otherwise intelligent conversations.

Thus, it’s become a haven for “trolls” leaving false, nasty and/or moronic comments. Would advertisers want to go near an often foul user experience?

On the plus side, Twitter offers a clever means of communicating. Members may post memos of up to 140 characters. Those wanting to see all of someone’s thoughts can sign up as a “follower.” To brighten up the product, Twitter recently added pictures to the user’s feed, formerly only text.

None of this cleans up Twitter’s growing reputation as a hideout for creeps, many specializing in hatred of females. In a celebrated case last summer, three British women — a classics professor, a member of Parliament and a feminist advocate — came under primitive assault for urging the Bank of England to put the image of the mannerly writer Jane Austen on some banknotes.

They were assailed with the usual “dumb bitch” insults and unpublishable allusions to body parts. But some tweets called for rape and painful death, threats serious enough to bring in police. Several men were arrested, ranging from a military instructor to an unemployed shut-in living with his girlfriend.

Twitter has responded by creating a “Report Tweet” button to flag a troubling tweet for review. That may deter death threats, but what good will it do for the pervasive lower-fever ugliness?

It does nothing about impersonators or “concern trolls,” a special breed of pest that does mischief pretending affinity for the target. A concern troll might write, “Who can blame Susan Rice for flaunting her superb figure in a fitted black suit?” You can’t call the social-media police on that, even if there were a social-media police.

The best defense, some say, is to ignore the trolls. “Don’t Feed the Trolls” may be sound advice for those who consider Twitter worth the affronts. But really, no one has to be on Twitter. So you wonder how the site’s numbers can grow if it’s become a protected playground for sickos.

Such websites are private property. They can set rules on who may enter their living rooms. The rules may leave room for a wide range of controversial opinion, but the owner decides.

But about 85 percent of the nastiest stuff (my number, plucked from the air) would simply disappear if participants had to attach their real identities to their words. Numerous news organizations have already banned anonymous comments. Twitter can do likewise.

“Identify yourself,” Twitter should demand of its posters. That or, as Jane Austen put it, “Let us have the luxury of silence.”

Froma Harrop is a syndicated columnist. She can be followed on Twitter: @FromaHarrop. She can be reached at fharrop@gmail.com.