An Islamic Centre in Muswell Hill was attacked in the early hours of Wednesday morning, and according to the police, the letters 'EDL' were found scrawled on the walls. Scotland Yard are believed to be looking into whether there is any link to the English Defence League.
If it turns out to be a racist attack, it adds extra significance to the Prime Minister's new task force to stop extremism in all its forms. Correctly, the focus will be on the Islamist variety, but Cameron pointedly mentioned the EDL as one of the groups that would be looked at carefully.
It is impossible to say anything at this point whether anyone from the EDL had anything to do with this. We await the results of any investigations.
Whatever emerges, this episode raises an important question - and one that Cameron's task force will need to grapple with: what does it mean to be part of the EDL? As I have argued elsewhere, the EDL is perhaps most accurately described as a social media group with a militant wing.
Behind the hundreds (or thousands in recent days) that demonstrate on the street, there is a much larger, highly motivated online community of sympathisers and supporters who blog, recruit, proselytise and organise.
But whereas the British National Party maintains exclusivity through formal lists and subscription fees, the EDL is the opposite: click "like" and you're in. The EDL does also have some more formal structures too, the local divisions who meet up periodically, their numbers are much smaller. There may be a few hundred of these active members - but there are over one hundred thousand Facebook fans.
The lack of any meaningful check on who joins makes it very difficult to know who is actually 'in' the EDL, and in what way. I've found in my work it ranges greatly, from people just concerned about violent Islamism, former football thugs who enjoy causing a bit of trouble on Saturday, to far nastier thuggish, racist elements.
It is alleged that Anders Brievik 'liked' the EDL on Facebook back in 2010. In recent days, there has been a huge surge in support for the EDL online. Who these new supporters are, or the strength of their link to the EDL, is not really known.
The EDL's official policy of non-violent, non-racist (if quite offensive) protest. But with this sort of loose franchise model it is practically impossible to ensure everyone follows the rules. When we talk about the EDL, this is the sort of movement we are dealing with - perhaps closer to a brand than a political party, without centralised control. That makes it far even harder for everyone - Tommy Robinson or the Prime Minister - to deal with.