Newham Council has been fined £145,000 after an employee sent out a mass email containing an unredacted version of the police database that ranks people's likelihood of gang-related violence.
According to the UK's data protection watchdog, some 203 individuals' personal data was shared with 44 people, and screenshots of the info was eventually uploaded to social media and seen by rival gang members.
The Information Commissioner's Office said it was "unnecessary, unfair and excessive" to share the unredacted version with so many people and that the risks "should have been obvious".
The bungle happened on the 17 January when a Newham Council staffer sent an email with an unredacted version of the Gangs Matrix, which had been shared by the Met as part of efforts to tackle violence.
However, the breach meant the 44 recipients – who included members of the council, its Youth Offending Team, and external public agencies and a volunteer group that responds to gang-related crime – saw personal details on 203 people.
The data breach was investigated as part of the ICO's wider probe into the Gangs Violence Matrix, which was set up by the Metropolitan Police in 2012 in a bid to reduce gang-related crime.
The ICO has already slammed the Met for "multiple and serious" breaches related to the database and ordered it to ensure it complies with data protection laws. The watchdog has now moved on to look at the way other bodies, including councils, use the information.
The unredacted version contained data that wasn't in a redacted version, which was also sent to Newham. This included ethnicity, home addresses, Police National Computer ID and whether the individual was a prolific firearms offender or knife-carrier. Both versions had a person's nickname, date of birth and alleged associated gang.
The ICO found that between May and September 2017, rival gang members had obtained photographs of the unredacted version of the Newham Gangs Matrix through Snapchat. Fifty high-risk offenders were on these photographs.
The watchdog noted that some of the people in this group were victims of serious gang violence, including one murder that happened in Newham during 2017 – although it emphasised it was not possible to say if there was a causal connection between the incidents.
However, the ICO added that this demonstrates "the significant harm and distress that can be caused when this type of sensitive personal information is not kept secure".
The police force within Newham borough share updated versions of the Gangs Matrix with Newham council and its Youth Offenders Team. The ICO said that, in principle, this is "sensible and appropriate" information-sharing given the roles of those organisations.
The Met said that the point of providing the redacted version of the database was so that it could be shared with other partners.
However, in this case, a staffer within Newham shared both versions, having simply forwarded the email they received from the Met police with the January version of Newham Matrix.
In May and September, two people, who are members of rival gangs, told their probation officers that they had photographs of the Newham Gangs Matrix – obtained via Snapchat – that showed the personal data of at least 50 high-risk offenders. The Met was able to establish this was the unredacted copy of the January Newham database.
Moreover, the council didn't report the breach to the ICO, it waited until December 2017 to launch its own internal investigation, and then failed to produce a final report of the probe.
Newham was also unable to identify any written policy or guidance on the handling, storage or decision-making related to the Gangs Matrix data that it received, and had not taken a number of sensible security measures.
The commissioner concluded in a decision notice (PDF) that Newham had been "grossly negligent" in its failure to comply with data protection laws, and handed it a £145,000 fine. ®