Conservative groups such as Pilf publish voters’ details online in what experts say amounts to ‘insidious modern-day intimidation’.

In June last year, Luis, a resident of Virginia, was astonished to discover that his name and personal details, including home address, had been posted on the internet by a group known as the Public Interest Legal Foundation (Pilf).

Luis’s data had been released by the group, along with hundreds of other names, as an appendix to Pilf’s two-part report called “Alien Invasion”. The front cover showed a UFO hovering ominously over a billboard on which the famous tourism slogan “Virginia is for lovers” had been photoshopped to read: “Virginia is for aliens”.

In lurid language, Pilf claimed that it had uncovered proof that “large numbers of ineligible aliens are registering to vote and casting ballots”. It warned its readers: “Your vote is at risk. New alien voters are being added to the rolls month after month, and swift changes must be made to ensure that only Americans are choosing American leaders.”