settling an argument, anyone have details?
Indicted, not arrested.
for what?
I don't think he was ever put in handcuffs if that's what you want to know 
He pled guilty to money laundering in January. His sentencing is apparently at the end of this month.
Seems it's related to a real estate deal he brokered.
http://content.usatoday.com/communities/mma/post/2011/01/reports-sonnen-admits-to-money-laundering/1