Many many companies in this industry attach real names and email addresses to this data, and even the ones that aim for pseudonymity do it typically in a very weak way (such as an unsalted md5 hash).
Do you have proof? At my previous ad tech employers data was always stripped of personal identifiable information. The legal and policy teams went to great lengths to ensure data was anonymous.
Many many companies in this industry attach real names and email addresses to this data, and even the ones that aim for pseudonymity do it typically in a very weak way (such as an unsalted md5 hash).