Privacy notices for services

Wi-Fi data collection- Footfall counters Lincoln City Centre privacy notice

This page explains how and why City of Lincoln Council and Lincoln BIG collects Wi-Fi connection data from mobile devices in Lincoln City Centre at the following venues.

Lincoln BIG- controlled

  • Castle Square
  • High Street (junction of Corporation Street)
  • High Street (outside Boots)
  • City Square

City of Lincoln Council- controlled

  • Sincil Street
  • High Street (outside Magistrate Court)
  • High Street (near Sibthorpe Street)

Wi-Fi data is used to provide us with detailed visitor footfall information helping us to primarily understand how busy the high street with view to monitor recovery post covid and the allocation of future funding needs.

It is not used to identify specific individuals or monitor browsing activity.

In summary, we are collecting data on how many mobile devices are counted by each footfall sensor, identifying them by a pseudonymised version of their MAC address.

We are trying to understand patterns of movement throughout the high street and how many visitors are seen daily.

We are not collecting data on browsing activity, cookies, phone numbers or whether any Wi-Fi services are used.

However, if you would like to opt-out, you can do this by turning off Wi-Fi on your device, turning your device off or putting your device into airplane mode.

What Wi-Fi connection data is

When a device such as a smartphone or tablet has Wi-Fi enabled, the device will continually search for a Wi-Fi network to connect to. When searching for a Wi-Fi network, the device sends out a probing request which contains an identifying number specific to that device known as a Media Access Control (MAC) address. This is what we mean by 'Wi-Fi connection data'.

How we collect it

When searching for WiFi networks to connect to the mobile device sends out a probe request. Our footfall sensors capture’s the probe request logs the MAC address, time and date the capture occurred and by which sensor. This data is then encrypted and sent to our footfall monitoring system.

How we make sure we cannot identify people

We will not be able to identify any individuals from the data collected. We have designed the process to identify patterns and to avoid identifying individuals. We are trying to understand how visitors as a whole use the high street.

All data collected is automatically depersonalised, using a one-way pseudonymisation process to ensure we are unable to identify any individual. This happens immediately after the data is first collected.

Pseudonymisation is the process of distinguishing individuals in a dataset by using a unique identifier that does not reveal their 'real world' identity. This is a way of protecting people's privacy in accordance with the Information Commissioner's Anonymisation Code of Practice.

Legal basis for using this information

Under privacy and data protection legislation, the Council is only allowed to use personal information if we have a proper reason or 'legal basis' to do so. In the case of Wi-Fi connection data, our 'legal ground' for processing this data is:

  • Our statutory and public functions
    • to undertake activities to promote and encourage safe, integrated, efficient and economic facilities and services.

Length of time we keep Wi-Fi connection data

We will retain any data collected in line with our data retention policies. This means that we will not hold information for longer than is necessary for the purposes we obtained it for. Depersonalised Wi-Fi connection data will be held for two years after the last time the device was recorded.

Keeping information secure

We take the privacy of our visitors very seriously. A range of policies, processes and technical measures are in place to control and safeguard access to, and use of, Wi-Fi connection data.

Each MAC address is automatically depersonalised (pseudonymised) and encrypted to prevent the identification of the original MAC address and associated device. At no time do we have access to a device's original MAC address.

All access is governed through industry standard authentication methods. Access is limited to a restricted group of users – only those whose access to the data is necessary for their role.

Our encryption keys are held securely in an industry standard computer program for secrets and key management, and we use an industry standard one-way hashing algorithm. All data is encrypted at rest and when in transit.

Sharing information

Individual depersonalised device Wi-Fi connection data is accessible only to a controlled group of Council employees and Proximity Futures (the council’s suppliers of the technology. Aggregated data developed by combining depersonalised data from many devices may be shared with other Council departments and external partners. Aggregated data will include counts of numbers of devices, rather than data containing pseudonymised MAC addresses.

We understand that there may be scenarios where the data could be useful to the police and other organisations that uses summarised footfall data. These types of requests will be dealt with on a strictly case-by-case basis to ensure that any disclosure is lawful.

We would only be able to disclose pseudonymised data, as we do not hold the original MAC address.

Your information rights

Please also refer to the guidance above on how to choose not to provide your device's Wi-Fi connection data.

In order to realise some of the benefits of collecting this data, it is important that visit patterns are understood over time. This means that we have to preserve our hashing key to maintain continuity of the pseudonymised data. It would therefore technically be possible to align the same MAC address to the same pseudonym. However, the only way we can determine a specific pseudonym is for the MAC address to be provided to us, as we do not retain the MAC address itself.

The rights under Articles 15 to 20 of the General Data Protection Regulation (GDPR) do not apply as we are not in a position to identify a specific individual, unless the individual provides additional information to enable identification. Only providing a MAC address does not establish a definite link between that individual and the pseudonymised visit information.

Even if we could associate a particular visit with a pseudonymised MAC address, we cannot assume the same individual was in possession of the same device during every visit. It would not be practical or proportionate to establish who was carrying the phone at each point in time.

This means that we are unable to provide data in response to any requests to access the Wi-Fi data generated by your device.

If you want to know more about your rights relating to your data or you have a query or complaint regarding the way, we have handled your data please contact our Data Protection Officer using the details below.

Data Protection Officer

City of Lincoln Council, City Hall, Beaumont Fee, LN1 1DD, email: 
Telephone: 01522 881 188

Regarding the counters owned and controlled by Lincoln BIG, the data collected is shared with City of Lincoln Council (see above for venues). Please contact Contact Us | Lincoln BIG

However, if you remain unhappy, then you have a right to complain to the Information Commissioner at: Information Commissioner’s Office, Wycliffe House, Water Lane, Wilmslow, Cheshire, SK9 5AF 
Telephone 0303 123 1113 (local rate) email