Hundreds of thousands of antisemitic posts were made online last year, with two-thirds of those found on Twitter, according to one study.
The World Jewish Congress, with the help of monitoring firm Vigo Social Intelligence, analysed millions of posts across Facebook, Twitter and more, spotting more than 382,000 antisemitic messages left online over the course of 2016. Of those, 63% were spotted on Twitter.
The high rate of hate speech isn't a surprise to anyone who has spent time online, with MPs accusing social firms of "peddling online hate" in the name of advertising revenue, with Google in particular facing pressure after government public awareness ads were shown next to terrorist recruitment material.
"We knew that anti-Semitism online was on the rise, but the numbers revealed in this report give us concrete data as to how alarming the situation really is," World Jewish Congress CEO and executive vice president Robert R. Singer said in a statement. "We hope this serves as a wake-up call to all internet forums to maintain moral standards, rid themselves of offensive content, and make the digital world a safer place for all."
The study didn't look at criticism of Israel.
The bulk of the antisemitic messages were spotted on Twitter, at two-thirds the total, followed by 16% on blogs, and 11% on Facebook. The larger proportion of such hate speech found on Twitter could be because it's easier to search for comments than other social sites - as many Facebook pages will not be public - and it's easy for individuals to open and run multiple accounts.
Asked for comment, Twitter responded by pointing to its work with the European Jewish Congress, its policies against hate speech, and its efforts to battle abuse, including new tools to mute accounts and staff training.
