Are high dividend stocks believable?

Certain stocks seem to provide double digit dividends, my question is how believable is this? Just because they paid that in the past it doesn't mean you can expect that in the future.

Shouldn't everyone just put all their money in Petrobras or Oxford square for 16% dividend payout - the fact they are not makes me suspicious..

On another note, anyone have double digit dividends stocks that have a high probability of paying out?