Organising a party on Facebook is usually not too much hassle, providing you don’t do what one teenage German girl did and forget to check your privacy settings.

A Hamburg birthday girl, identified only as Thessa, got quite a shock over the weekend as her sweet sixteen birthday invitation went viral and she received 15,000 ‘confirmed guests. In the end, 1,500 guests showed up at her doorstep, not to mention 100 horse-bound police officers.

After discovering her faux pas, Thessa’s parents quickly moved to cancel the party and even hired a private security firm to protect their home for last Friday night. According to police spokesman Mirko Streiber, however, it wasn’t enough.

"We had cordoned off the house, some 100 police were on the ground, four of them on horses — but that did not keep the kids from celebrating," Streiber told the Associated Press. “It was sheer insanity but mostly peaceful”.

Thessa’s absence did not go unnoticed, as some partygoers held up signs wondering “Where is Thessa?" and others even went to the effort of bringing homemade cake. Some of the unwelcome guests also began chanting "Thessa, celebrating a birthday is not a crime".

You can take a look at all of the the madness in the embedded clip below. Evidently, there isn't much to do in Germany on a Friday night: