I think this happens pretty much everywhere a mobile carrier can profit from selling data about who&#x27;s doing what.  For example, Norwegian company Mobiletech.no has API access to the largest, Nordic mobile carriers&#x27; billing gateways and can turn an IP address:port pair from an HTTP&#x2F;HTTPS connection into a MSISDN, sometimes with additional subscriber details.  They&#x27;re working with advertisers and analytics companies to help them count mobile subscribers instead of unreliable, cookie-based visitors.  Similarly, mobile carriers in Denmark have been caught injecting HTTP request headers which leaked the subscriber&#x27;s phone number, phone model, etc to arbitrary web sites.  In Sweden, someone used a similar service to blackmail visitors who watched porn.