G4S is the largest employer on the London Stock Exchange and the third largest private sector employer in the world.
With 625,000 employees operating in 125 countries, the company's empire covers an incredible, unparalleled array of high-profile, high-risk and high-margin contracts.
This includes everything from operating prisons, armoured vans, rock star security, protection from Somalian pirates to airport security in Vancouver.
G4S secured a 10-year, 370 million dollar contract to replace front line police officers in Linconshire, UK. It's their own employees and not cops who transport arrested offenders, fingerprinting them and holding them in their own "custody suites".
But G4S's rapid and aggressive expansion has led to scrutiny and scandal.
G4S admitted in to a home affairs select committee their failure to supply enough security guards for the London Olympics was a "humiliating shambles."
The Serious Fraud office is pursuing a full-scale criminal investigation for alleged over billing of the UK government for prisoner services - except the prisoners had left the country, even passed away. G4S for their part, offered restitution.
And three G4S guards were found to use unreasonable force and acting in an unlawful manner, resulting in the death of an Angolan man as they restrained him during deportation.
This is the firm, who up until this weekend, was responsible for the security of the men, women and children in detention by the Australian government at Manus island where riots left one man dead and scores injured.
Their contract, negotiated under the Rudd government, required G4S to hire a quota of local PNG subcontractors in security.
The contract has now expired.
Transfield Services won a 1.2 billion contract to take over security, subcontracting it out to Wilson Security like they did whist in charge of operations at Nauaru.
Wilson now has 181 security guards on Manus Island; fresh boots on the ground, but those boots still belong to private security firms.
Thousands of Australians marked the death of Iranian detainee Reza Berati by holding candlelight vigils around the country last night.
Many believe accountability for Australian government border protection programs should lie in one place - with the government itself.
