Men with weapons are more dangerous than men without therefore weapons are dangerous.
Men with pencils are more dangerous than men without therefore pencils are dangerous.
Note that according to the definition of a weapon ("a thing designed or used for inflicting bodily harm or physical damage") a pencil can be classed as a weapon due to its use. Which is a perfect illustration of why men with pencils (used as weapons) are more dangerous than men without.
So thank you for making my point.
"There are no dangerous weapons; there are only dangerous men."