Dating apps are increasing rates of sexually-transmitted infections and could lead to an explosion of HIV, a leading sexual health doctor has said.
Dr Peter Greenhouse, from the British Association for Sexual Health and HIV, said apps "have to invest more time in pushing a safe sex message".
He told the BBC's Newsbeat: "You are able to turn over partners more quickly with a dating app and the quicker you change partners, the more likely you are to get infections.
"What really worries me is that we are just at a tipping point for HIV.
"If enough people change partners quickly, and they've got other untreated sexually transmitted infections, it might just start an explosion of HIV in the heterosexual population. Apps could do that."
Alongside Tinder, Happn is one of the UK's most popular dating apps.
Marie Cosnard, head of trends at the company, said apps were not to blame.
"Dating apps are following wider social trends and changing behaviours that have been unfolding for decades," she says.
"There's a liberalisation of attitudes towards the number of partners, the status of relationships, towards marriage, divorce, etc.
"So the rise of any STI is not really connected to dating apps themselves. The problem is much wider.
"People need to be more educated in terms of sexual health and to take their responsibilities, no matter how and where they've met their partner."
George Kidd, chief executive of the Online Dating Association, told Newsbeat: "Our members are dating sites, not sex-encounter businesses, but we should be alert to any particular situations in which health advice is appropriate."
According to Newsbeat, it is estimated that up to two new dating apps now launch each week in the UK.
There are specialist apps for threesomes, swingers, religious groups, affairs and even ones that reveal your STI status before you meet.