There are no dangerous weapons; there are only dangerous men.
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."