It seems that EUReferendum is being leant upon by lawyers Mishcon de Reya—acting on behalf of that great philanthropist, Rajendra K Pachuri.
It seems that Dr Pachuri has taken exception to this extensive Telegraph article, as well as EUReferendum's constant exposures of the gentleman's nexus of contacts, power, money and severe conflicts of interest.
If in doubt, reach for the lawyers, eh?
UPDATE: Bishop Hill thinks that it may, in fact, be Tata doing the suing, rather than Pachuri. In which case, Pachuri will probably sue me for saying that it was him doing the suing. Or something.