Millions of love-seeking Australians are at risk of having their photos and personal details exploited online, a consumer group warns.
An investigation by Choice has found that many dating websites have "extensive and confusing" terms and conditions which leave the door open to members' private data.
"People may sign up to these sites looking for love and companionship without realising that they are also giving permission for personal information to be shared with others or their browsing habits to be tracked," Choice spokeswoman Ingrid Just said.
"Once you agree to certain dating websites' terms and conditions, your profile and your photo can be used for advertising and even passed on to third parties."
The consumer group is calling on the websites to allow members to specifically choose whether they want their information to be passed on, and to have terms and conditions more prominently displayed during the sign-up process.
Ms Just said users should be also be wary of scammers who sometimes pose as legitimate site members.
Choice's investigation included RSVP, eHarmony, Oasis Active and OkCupid, all of which offer both free and paid memberships.