Professor Zoom wrote:
For celebrities, Twitter does to a verification. Generally it'll have like a green or blue check mark next to the name, meaning it's been a verified profile. So, yes, 100% certain.
I was tongue-in-cheek in my reference, however there are still a number of bogus profiles out there and not everyone is aware of the check mark verification. We hear about bogus announcements being made all the time in famous people's names. Which has led to a few people (Jenna-Louise Coleman being one) having to announce publicly that they don't have a Twitter account. And you still end up with scenarios like Nicola Bryant needing to use "The Nicola Bryant" as her username because of others using just "Nicola Bryant" (though to be fair that's also often because someone with the same name is legitimately registered; I couldn't tell you if this was the case with Nicola). And there's nothing stopping someone joining a forum (maybe not this one or Gallifrey Base because we have enough people in the know here and there who could probably suss out a faker pretty quickly, but there are millions of forums out there) claiming to be Peter Davison or, well, Miranda Borman.
There are enough sources that can be used to verify, for example, which Karen Gillan is real on Twitter. Or Moffat. But it's still hardly a foolproof system. Ditto Facebook.