This is a term commonly used to describe one of those fans of Star Wars who has absolutely no grip on reality.
This may or may not be because of Star Wars. Other influences may include drugs, upbringing, and general stupidity.
You can spot a Ben Skywalker by how they argue.
If arguments tend to devolve into something like this:
"I think you are wrong because your opinion is unfounded and completely lacks evidence!"
"May the force be with you!"
You are probably arguing with a Ben Skywalker.
Ben Skywalkers tend to have little or no common sense, and are unwelcome just about wherever they go.
Other than being obnoxious fanboys, they are extremely opinionated, and love to start pointless arguments about the molecular components of the Millennium Falcon's warp drive.
They constantly complain about nobody responding to their e-mails or Private Messages, are just LOOKING for perma-bans at any intellectual forum, and are a general nuisance.
If you see a Ben Skywalker, prepare to either run or suffer a massive IQ drop.

A pubic hair piece. A toupee for the pubic area/genitals. In the 1700’s when mercury was used to treat sexually transmitted diseases (Gonorrhea or Syphilis) one of the side effects was the loss of pubic hair. To disguise this condition, that was not cured by mercury, a Merkin was employed.