"Mumsnet founder Justine Roberts and her family were woken in the early hours of the morning last week by armed police at the door. Days later, more armed police arrived at the address of a Mumsnet user. In both cases, police had received calls claiming there was a gunman at the property. In both, said gunman did not exist."

Turns out you’re right, and “ Roberts and the Mumsnet user were the first known UK victims of "swatting"”. The first.

Although it still sounds like something very different from the real swatting, in that the police didn’t pose danger to inhabitants.