It depends which site you're referring to, some are safer than others. I think that the dating world in and of itself isn't safe, but that's ubiquitous for all women dating. If you decide to converse with people online, your communique could be trace-routed to your IP address, but using free wifi has a host of other problems. I don't think most people in the online dating world are that into hacking the people they match with. But it is another portal to Adopt-A-Stalker. The rub is finding the balance between throwing yourself out there on the mercy of the world and hiding in a cave of solitude.
TLDR: Try a service that allows stages of anonymity, and traverse its dating pool until you are made uncomfortable. Trust your own judgement about creeps. Be safe, and good luck. 😉