An anti-spiking squad is touring pubs and clubs in Chesterfield to warn revellers to be on their guard.
Police are warning how easy drink spiking is
The team is placing stickers on unattended drinks at venues across the town over the busy festive period.
The group, made up of volunteer bar staff, hope the brightly-coloured stickers will show how easy it is for someone to spike a drink.
Pc Richard Illingworth said: "What we are trying to do is concentrate on the simple issue of personal safety."
The scheme is being co-ordinated by Derbyshire Police.
Stickers bear the slogan: "Who's watching your drink?"
PC Illingworth said he hoped the team would highlight the dangers of people leaving drinks unattended.
"What we are trying to do is concentrate on the simple issue of personal safety," he said.
"What we want to do is use bar staff to get that across rather than people be distracted by the police uniform.
"It's a bit like the bar in a Wild West film. The out-of-towner guy comes in and the piano stops playing.
"That's what happens when the police go in a pub. The bar staff go in and everyone carries on."