A daring 2007 heist targeting a heavily secured data center operated by international telecoms giant Verizon has been brought to light, revealing a meticulously planned operation that yielded sensitive banking data worth an estimated $100 million.

The robbery, later described by its ringleader Terry Ellis as his "criminal Mount Everest," involved bypassing eight levels of security at the King's Cross facility. The gang, disguised as police officers and accompanied by a large Alsatian dog named Buster, infiltrated the building to steal computer chips containing highly sensitive financial information.

Ellis, whose father was also an armed robber, had a childhood history of petty theft before escalating to armed robbery and drug smuggling. He sought a more significant challenge to "take the art of robbery to the next level," which he achieved with the Verizon data center job.

The heist was commissioned by a "banking syndicate" in the U.S. seeking to erase evidence of their alleged illegal involvement in funding construction projects in Ireland, potentially linked to the subprime mortgage crisis that later triggered the global financial crisis. The fixer representing the syndicate emphasized the catastrophic consequences if the data fell into the wrong hands and insisted the operation appear as an "opportunist robbery."

The gang, which included four computer technicians and a tenth member knowledgeable about data extraction, was tasked with removing 80 servers. They were paid £1.5 million (equivalent to $3.6 million today) for the job, a figure Ellis noted seemed less generous given that three prior attempts to access the data had failed.

Security at the Verizon complex was extensive. It featured swipe-card and biometric scanners, a pressurized airlock, multiple turnstiles, bullet-proof glass, and continuous CCTV monitoring. Guards patrolled the premises, and an external private security company remotely monitored computer data rooms. The data center was particularly vulnerable as it did not have offsite backups, a standard security protocol at the time.

The thieves spent weeks observing the building, identifying blind spots in camera coverage. An idea for the infiltration emerged when Ellis witnessed police blocking off a street for a man on a library roof, sparking the plan to use a false police emergency to gain access.

The gang acquired five sets of new police uniforms, radios, and a police van and car from a film-props company. On the night of December 6, 2007, they staged a mock police response, with uniformed "officers" approaching the data center's entrance. Ellis, posing as a police officer, claimed they were responding to a report of an intruder on the roof.

After gaining entry, the robbers handcuffed the security guards, claiming it was a precaution due to the supposed intruder's attire. They then allowed the technicians and other team members into the building. Ellis and a confederate secured two more guards on the top floor. He then cut the live CCTV feed and falsely explained the outage to the monitoring company as a power surge.

The technicians, using the guards' ID cards, accessed the data room and disconnected the targeted servers, placing them into laundry bags. They subdued a total of 16 staff members, including technicians and cleaners.

The gang exited the building by 10 p.m., narrowly avoiding two incoming technicians who did not notice anything amiss. As they drove away, they observed a large police convoy heading towards the data center, alerted by the alarm system.

Despite their successful escape, Ellis and his second-in-command, Denis Carr, were later identified by Verizon security guards from photos related to another robbery investigation. Ellis was arrested in September 2008 while attempting to flee the country. He was sentenced to over eight and a half years for the Verizon heist and three other robberies. The court noted that staff members required treatment for shock after being threatened with the dog.

Ellis claims he was visited twice by MI5 in prison, who offered to reduce his sentence if he identified the recruiters for the data theft. None of the stolen servers have ever been recovered, and only Ellis and Carr have been prosecuted.

The story of the elaborate King's Cross heist has inspired the novel "Cloudthief" by award-winning American writer Nathaniel Rich. The novel centers on a duo attempting to steal valuable data from a data center in Tulsa, Oklahoma. The article notes that data centers have become a significant engine of global economic growth, powering the internet and artificial intelligence industries, making their security more relevant than ever.