Rupert Murdoch tweets about Islam and the future of David Cameron

Billionaire publishing and broadcasting tycoon Rupert Murdoch has always had a bellicose side to his personality.

In 2003, Guardian columnist Roy Greenslade reported that all of his 175 papers supported the U.S.-led attack on Iraq.

"We can't back down now, where you hand over the whole of the Middle East to Saddam," Murdoch told the Sydney Daily Telegraph at the time. "I think Bush is acting very morally, very correctly, and I think he is going to go on with it."

Over the weekend, Murdoch was at it again, criticizing British prime minister David Cameron for going on vacation in Spain while the U.K. was on a terror alert.

The Australian-born tycoon also declared that what's said inside some mosques is "really scary"—without revealing which ones he's ever visited.

Then he cited the Koran in suggesting that whoever kills a human being should be regarded as having killed all mankind.

Back on May 22, Murdoch tweeted that the killing of a British soldier "will be a big test for Cameron".

"Could save him or finish him off if he mishandles," the media magnate added. "Public rightly scared and outraged."

Politicians who cross Murdoch sometimes don't last long in the U.K.

One of the businessman's tweets notes that even the Spectator magazine is speculating about a potential challenge to Cameron.

"After three years what will be his legacy?" Murdoch wrote ominously.

Cameron had better hope that Murdoch's reporters aren't listening in on his phone calls, or else the end could come sooner than the Conservative leader might expect.

Cameron probably didn't endear himself to Murdoch when he ordered two inquiries into the phone-hacking scandal by News of the World staff and media ethics in Britain.

"To be fair, it is difficult for politicians to call for more regulation of the media, because if we do so, we're accused of wanting to stifle a free press or even free speech," Cameron said at the time. "But the deeper truth is this: there is a less noble reason."

He went on to say: "Because party leaders were so keen to win the support of newspapers, we turned a blind eye to the need to sort this issue, get on top of the bad practices, to change the way our newspapers are regulated."

And now Murdoch is tweeting about how Cameron could soon be finished. It's a sign that payback time could not be far away.