Bank executives beware. Turn your microphones off during what are likely to be stormy shareholder meetings this year.

Insults are likely to fly at many bank AGMs this year from shareholders angry at their board for losing billions, sending shares crashing, making ill-advised purchases or for their role in the global economic crisis. Bankers are unpopular after more than a year of grim news.

But an unnamed director at Santander lacked humility this week.  After heated questions from the floor about the Spanish bank’s purchase of U.S. lender Sovereign and its exposure to the alleged Bernie Madoff fraud, some shareholders applauded a critical comment.

“Bastards. Listen to them clapping,” the director was heard saying after his mic was left on.

It rekindled memories of Jeffrey Skilling, the disgraced head of Enron who once called a critical analyst an “asshole” in an earnings conference call. But shareholder meetings are often stormy in Spain, and there has been little backlash, whereas in Britain and elsewhere the latest comment could have prompted a bigger furore and a hunt for the culprit.

But it serves as a reminder to executives to put their hard hats on when they meet shareholders this year.