Back in 2003, Labour Member of Parliament Chris Bryant did something others dared not do: He asked Rebekah Brooks, then editor of the Rupert Murdoch-owned tabloid The Sun, whether her newspaper ever paid off the police.

When she admitted “we have paid the police for information in the past,” Bryant attempted to push further, but the committee chairman shut down the hearing. His attempts to get newspapers interested in the story went nowhere. None would bite.

Six months later, he got “monstered” by News International papers. “They hacked my phone,” says Bryant. “And they ran some pretty hideous stories about my sexuality.”

“Tabloid journalism requires a constant supply of victims,” former Labour MP Chris Mullin explained to FRONTLINE. “It doesn’t really matter whether they’re celebrities fallen on hard times or committing adultery or footballers who are in trouble for one reason or another, or errant politicians. … They decide who the victims will be, and you get monstered.”

Why? It’s not just about political power or revenge, explains Andrew Neil, the former editor of the Murdoch-owned Sunday Times.

“There are two currencies in the Murdoch organization,” he says.  “One is money, the second is gossip.  And Rupert Murdoch loves gossip.”

But it’s gossip — and, more specifically, how News International reporters and private investigators obtained it — that’s put Murdoch’s tabloid empire in peril. The clip above is from tonight’s film Murdoch’s Scandal, an investigation into how the News of the World phone-hacking scandal unraveled. Check your local listings here, or watch it online tonight, starting at 10 pm ET.