From the English "anglo-", meaning "English" and the l33t15h "owned", meaning "to have one's ass handed back to them on a plate". Anglowned means to completely own some dumbass who can't spell or use sentence structure.
"hi guyez im riteing a book adn i ned sum ideaz 4 namez ken any1 hlp plz kthx???????"
"Well if you're writing a book I hope you can actually spell..."
"Oh snap, you got anglowned by a Dutchman."