Picture the scene: a young man charges at a government minister and is removed by security while kicking, screaming and spitting antisemitic abuse at the audience.
Earlier this month I witnessed this disturbing sight first-hand in the chamber of the supposedly genteel Oxford Union - the "last bastion of free speech".
Unfazed by the incident, many students in the braying crowd continued to scream at the speaker, Israel's Deputy Foreign Minister Danny Ayalon, and attempted to mob him on his way out. Make no mistake: the atmosphere was not one a nice Jewish boy would feel comfortable in.
It is an unfortunate fact that no Israeli government official seems able to speak at a British university without vocal protest and interruption. Shimon Peres's lecture at Oxford in November 2008 was regularly marred by co-ordinated protestations.
However, it is sometimes only under closer scrutiny that the latent antisemitism at the fringes of anti-Israel activism on UK campuses becomes clear.
There are, of course, many students involved in anti-Israel activism who protest purely as a political gesture, albeit often a naïve one.
But it is not "just political", as many claim, to chant "Palestine will be free from the river to the sea" and call for the expulsion of Jews from Israel, as I heard at the Oxford Union.
It is not "just political" to attempt to threaten or attack visiting speakers. Those who are genuinely interested in the political process understand it is driven by debate, not intimidation.
It is not "just political" to boycott Holocaust Memorial Day "due to the treatment of the Palestinians", as speakers due to lecture at both Oxford and Cambridge have done.
Yet all of these abuses are taking place on campuses in the name of political activism.
What can we do as students? We have a duty to ensure that our student unions live up to their stated goal of representing all their students.
Too often, "politically-motivated" antisemitism is ignored by student unions fearing that condemning it will make them partisan.
Oxford University Student Union's "measured response" to the Ayalon melee was to oversee the student who screamed the abuse defending his actions in the SU newspaper.
No statement was issued condemning the allegedly antisemitic remarks, despite calls from hundreds of students demanding such a response.
Silence from student unions when the law is broken by anti-Israel activists is not a new phenomenon. The "occupations" of university buildings across the country after last year's Operation Cast Lead were, without doubt, implicitly supported by the unions which largely refused to speak or act against them.
If we continue to allow our student unions to condone such incidents out of a misguided sense of political neutrality, we are in turn allowing them to take place.
The silence of the student unions is undoubtedly more harmful than the shouts of the protestors could ever be.
