Wait, what? My friends might be setting up a profile for me without even knowing it? I sure hope that's qualified by "if I'm signed up", because otherwise I might need to engage in some rage.
They can already matchmake you without you knowing it offline; what's the difference if it's online? Presumably they wouldn't be allowed to use your real name or super-identifying photos or anything, so this "dating persona" they set up from you is divorced from the rest of your identity, and nobody will find it by looking for you.
The difference is that if it's not online, then it's purely interpersonal; a social, private, ephemeral (as in not recorded) sort of activity. But if it's online it's like publishing something in public; it's broadcast to a large number of strangers and it's recorded for a long time. Big difference, I would say.