Is 'mong' an offensive word?

[Fenster]

Gervais, and his like, clearly get away with humor the seventies mob get castigated for in these "advanced" politically correct days. (Gervais mob know it's offensive and are taking the piss out of the people that don't get it )

Mong has always meant a spastic to me. Gervais knows it means spastic too. Look at all the "mong" faces he's posting on twitter.

The question is - who is SERIOUSLY offended by this? Fucks sake