Crimes such as rape, sexual assault and harassment have all been linked to dating apps Tinder and Grindr by West Midlands Police.
Officers have also investigated incidents of indecent images of children and threatening messages being sent via the popular sites.
A Freedom of Information (FoI) request to West Midlands Police revealed an increase over the last couple of years with nine incidents recorded so far in 2016 compared to just one back in 2012.