write tweets that insult, harass and threaten their targets. Last week, the Anti-Defamation League issued a report detailing the widespread use of Twitter to harass journalists with anti-Semitic messages during the 2016 campaign. Twitter executives are wrestling with how to deal with the trolls without undermining Twitter's commitment to free speech.

A little later in the show I'll talk about this with BuzzFeed tech reporter Charlie Warzel, who's written a series of articles about harassment on Twitter. But first, we're going to hear from a writer who's received countless harassing and threatening tweets. David French writes for the conservative publication National Review and is a senior fellow in its think tank arm, the National Review Institute. He has been and is still being trolled for his critical comments aboutAnn Coulter, the alt-right right and Donald Trump.

He's part of the Never Trump movement. And Bill Kristol even suggested that French consider running as a conservative alternative to Trump early in the campaign.

David French, welcome to FRESH AIR. Tell us first what set off the attack by trolls.

DAVID FRENCH: Well, first, thanks very much for having me. I've been listening to FRESH AIR for many years. It's a privilege to be here, although not under these circumstances. What set off the attack by trolls was really something pretty simple.

In September or mid-September of last year, I had noticed that Ann Coulter, who is a very prominent supporter of Donald Trump, was tweeting out a lot of thoughts that are common to this part of the right - even