Checkoway's law
The law states, "Whenever anyone tries to correct another's spelling, grammar, or punctuation online, he invariably screws up his own."
An example of Checkoway's law in action:
A: The woman that sings in the band is great.
B: You mean "The woman _who_ sings in the band is great." Learn some english grammer!!
A: The woman that sings in the band is great.
B: You mean "The woman _who_ sings in the band is great." Learn some english grammer!!