See this paper "Header Enrichment or ISP Enrichment? Emerging Privacy Threats in Mobile Networks": http://conferences.sigcomm.org/sigcomm/2015/pdf/papers/hotmid

See this paper "Header Enrichment or ISP Enrichment? Emerging Privacy Threats in Mobile Networks": http://conferences.sigcomm.org/sigcomm/2015/pdf/papers/hotmiddlebox/p25.pdf http://conferences.sigcomm.org/sigcomm/2015/pdf/papers/hotmi... For example Orange in Jordan adds an HTTP header with the phone number of the client to every connection. And there are technical people out there still saying HTTPS/TLS should not be mandatory…