A friend insists that, while Shakespeare existed, he isn't responsible for most of the works attributed to him. Rather, a collection of various playwrights penned them.
Arguments were the sheer volume of written material being implausible, and the fact that his hometown isn't mentioned in any of his texts.
I am not discouraging any new answers coming in, but I think /u/texpeare's answer about this will be interesting and helpful to you. The short version - it's BS.