One can find statements criticising Israeli policy that do not need a disclaimer or any other sort of qualification to determine that they are not anti-Semitic (and in many cases highly unlikely to be motivated by anti-Semitism) by typing 'Israel', 'Israeli' or 'Netanyahu' into Twitter's search box. Of course, it's also not difficult to find statements that are probably or unambiguously anti-Semitic using the same search terms...

For all Twitter's shortcoming as a means for making nuanced arguments and the sensitivities of commenting on things Israelis and Palestinians have done without being accused of rationalising the excesses of the other side, it's not exactly difficult to convey dismay over a particular attack, disgust with an Israeli policy, support for Palestinian statehood or opposition to a statement made by an Israeli in 140 characters without blood libels, gloating about Israeli kids going missing or rants about a concept of 'Zionism' that owe more to the 'Protocols' than reality. Indeed enforced brevity would tend to lead one towards not including that sort of extraneous anti-Semitic sentiment.

Sure, Twitter is an utterly terrible medium for making carefully reasoned arguments about how to reconcile conflicts and redress grievances, but on the other hand it's a fantastic medium to rant and have the "I was misinterpreted" defence if anyone ever suggests your abusiveness towards the other side of the debate goes too far. Academics are certainly not immune to enjoying a rant about their enemies.