The AIDS Healthcare Foundation is defending an ad campaign in Los Angeles that links popular dating apps with the spread of sexual transmitted diseases. The group has sponsored billboards and bus benches that are aimed at reminding users about the risks of casual sex and offering free STD tests.

"In many ways, location-based mobile dating apps are becoming a digital bathhouse for millennials wherein the next sexual encounter can literally just be a few feet away — as well as the next STD," Whitney Engeran-Cordova, senior public health director for the foundation, said in a statement.

Tinder sent a cease and desist letter claiming the campaign falsely associates the dating app with the spread of venereal diseases: "These unprovoked and wholly unsubstantiated accusations are made to irreparably damage Tinder's reputation in an attempt to encourage others to take an HIV test offered by your organization," a lawyer for Tinder wrote.

The foundation sent a letter to Tinder denying that it disparaged the company and saying it would not remove the reference to the app. Read More via AP