Festive drinkers are receiving phone messages warning them of rape risks as part of a hi-tech awareness initiative by police.
Scotland Yard is harnessing the power of WiFi hotspots to send digital messages to revellers at some of London's most popular nightspots.
Officers hope the technology can help prevent sex attacks and boost personal safety in some of the capital's busiest clubs, including the Ministry of Sound, Proud Galleries and Infernos.
Detective Supt Jason Ashwood said: "This concerted prevention drive is about sending a message to perpetrators of rape that sex with someone who is unable to consent is rape. If a person is unconscious or their judgment is impaired by alcohol, they are legally unable to consent.
"Men and women should never feel that they cannot enjoy themselves on a night-out, however we would always advise people to take care of themselves and their friends and ensure they are comfortable with their surroundings and situation. Have fun, but be responsible and stay safe.
"This is about us trying to prevent offences from happening in the first place."
The initiative, taking place in Westminster, Camden, Southwark and Lambeth, is advertised via posters asking partygoers to switch on their mobile phones' WiFi facility. Alerts are then sent to phones asking the user to download a police message.