Georgina Hobday had invited 100 people to her parents' townhouse in Brighton for a party modeled on those in the TV show "My Big Sweet 16." Michael and Sylvia Hobday had drafted four adults to keep out unwanted guests Saturday night, but they were unable to cope with the crowd that appeared, the Daily Mail reported.

Eventually, 20 police officers got the gatecrashers under control. But in half an hour the uninvited guests trampled the garden, broke mirrors with their heads and scorched curtains and rugs with cigarette ends.

"It was an absolute horror show, I will never have a party for my daughter here again," Sylvia Hobday said. "She had no idea who most of the people were and they were rampaging through the house."

She said there was no alcohol in the house when the party started, but the gatecrashers arrived with plentiful supplies.

At least some of the crowd were believed to be members of a group called the Facebook Republican Army which uses social networking sites to find parties to crash.