The scandal began in 2006, when the Metropolitan Police laid charges against the News of the World's royal editor Clive Goodman, and Glenn Mulcaire, a private investigator, alleging that they intercepted voicemail messages left for members of the royal household. Both men were jailed in 2007. Allegations against the News of the World in relation to illegal voicemail interceptions have continued in subsequent years, implicating other journalists and staff at the paper; numerous public figures, including politicians and celebrities, were found to have been targeted by the interceptions.
In July 2011, further allegations were made that the News of the World hacked into the voicemails of murder victim Milly Dowler, as well as victims of the 7/7 attacks and relatives of deceased British soldiers. The news was met with public outrage in the United Kingdom. [source: Wikipedia]
Two newspaper hacks (nothing to do with phone hacking—hack is a derogatory term for a someone who writes for money without much concern for the quality of what they write) are seen outside the headquarters of News International (News of the World's parent company). One of the hacks has hacked into Rupert Murdoch's phone and discovered that they are about to be fired—for phone hacking, we can assume. (Rupert Murdoch is the Australian-American media mogul and the Chairman and CEO of News Corporation.) The humour comes from the irony of the situation.