Indeed, what @MarcP said, but there's a but:
"Location data is largely captured per device using that device's media access control (MAC) address as a unique identifier. As part of a privacy technique, some mobile operating systems have added functionality that attempts to randomize the WLAN MAC address a device uses, making it more difficult to track by solutions such as Meraki Location Analytics. As the number of mobile devices that implement randomization increases, solutions to detect and locate devices have changed. Meraki provides additional capabilities such as bluetooth information via the Meraki Scanning API, enabling Meraki customers to anonymously include wearable devices as part of their location analytics dataset."
Source:
https://documentation.meraki.com/MR/Monitoring_and_Reporting/Location_Analytics