Someone unknown has joined out world, one of us thinks it's herobrine, but im not sure.

We have been trying to find Herobrine in Minecraft, we've been to the Farlands and someone chatted, their username being our's expect the '<' and '>' are '[' and ']', is this herobrine, or a hacker playing games with us. Their username is TheAnarchism934 or TheAnarchism, some people think it is Herobrine, but I think that's a really terrible opinion, please help. Now, it says they've been banned from our worlds' database, but that's happened with a previous person last week, is this real?