Vehicle Registration Plate Surveillance System: How it spies on you

No CCTV has teamed up with Privacy International and Big Brother Watch to challenge the legality of the Automatic Number Plate Recognition (ANPR) [also known as ALPR in North America] camera network in the UK. A complaint has been sent to the Information Commissioners Office (ICO)against a so-called ANPR “Ring of Steel” that is being constructed around the town of Royston in Hertfordshire — but for Royston read any town in the UK.

Background

The Association of Chief Police Officers (ACPO) has constructed a network of cameras across the country without any public or parliamentary debate. These cameras record the number plate of each and every vehicle that passes, sometimes taking a photograph of the car and its occupants. The number plate is then compared to a “hotlist” of vehicles of interest, and whether or not the plate is on that list (ie a “hit”), all information gathered is stored for between two and five years. A Hertfordshire Police Authority report reveals the details of the data retention periods:

Currently number plate pictures are held for 2 years. Car pictures are held for 90 days. “Hits” information on text and number pictures are held for 5 years and car pictures are held for 2 years.

['Final report of the Topic Group on Automatic Number Plate Recognition (ANPR) Technology use within Hertfordshire Constabulary', p. 9]

The data collected from number plate cameras can be linked to multiple databases such as the Driver and Vehicle Licensing Agency (DVLA) database and the Motor Insurance Database Application System (MIDAS) which in turn can be used to identify the owner of the vehicle. The resulting database of vehicle movements can then be data-mined by the police to look for patterns or track individuals. The police are at great pains to state that they do not target law abiding motorists, but the system has the potential to be a mass surveillance tool and if the police are not interested in motorists who are not on hotlists then it begs the question why do they gather this information.

The National Policing Improvement Agency(NPIA)’s ANPR web page states:

At the end of March 2011, the NADC was receiving approximately 15 million reads per day, with over 11 billion vehicle sightings stored. This body of information on vehicle movements is key to the value of ANPR.

Data Mining

The data collected from ANPR cameras is stored in databases at the local police force level, known as Back Office Facility (BOF), and also in a national database called the National ANPR Data Centre (NADC). Up until now many campaign groups have focused their criticisms largely on the national database but the complaint by No CCTV and co also highlights issues with the local databases. It is the local BOF databases that can be used alongside data mining tools such as those developed by Northgate Public Services.

Our complaint quotes Northgate Public Services’ brochure The ANPR Intelligence Dividend, which states:

Northgate’s Advanced Data Miner enhancement for BOF 2.3 allows users (not just analysts) to access the 2% of reads that result in hits, but more importantly, to access the 98% that offer intelligent leads. A senior investigating officer on a major crime will be very interested in that 98% because they will be able to say “don’t tell me what I now, tell me what I don’t know”.

['The ANPR Intelligence Dividend — Northgate BOF 2.3 Advanced Data Miner', p. 1]

The original rhetoric used to sell number plate cameras was that they could “deny criminals the use of the road”, but the involvement of Northgate Public Services shows that the ANPR network is potentially about much more than spotting uninsured drivers and could easily be used as a mass surveillance tool.

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