Senators from both parties sent letters to major digital ad exchanges, including Google and Twitter, on Friday, asking whether user data was sold to foreign companies that might use it for blackmail or other malicious purposes.
Hundreds of companies receive a user’s personal information, including search history, IP address, age, and gender, as part of the real-time bidding process to determine which targeted ads a user sees when a web page loads.
According to the office of Senator Ron Wyden, a Democrat from Oregon, questions about the selling of data gathered during the auction period were also sent to AT&T, Index Exchange, Magnite, OpenX, PubMatic, and Verizon.
In letters to the firms, Wyden and other senators wrote, “Few Americans know that some auction participants are syphoning off and storing ‘bidstream’ data to compile comprehensive dossiers on them.”
“Foreign intelligence services may use this knowledge to warn and supercharge hacking, blackmail, and influence operations.”
According to the senators, data such as user locations, computers, and web usage can be gathered because online ad exchanges use automated bidding systems to decide which advertisements to show people using internet services.
“These dossiers are being freely sold to anyone with a credit card,” the senators wrote. “This includes hedge funds, political campaigns, and even governments.”
According to the release, questions submitted to the companies included what information is collected about people in the process of serving advertising and which international firms have purchased such data from them.
The deadline for the companies to react was set for May 4th.
Twitter confirmed to AFP that it had received the letter and would reply. The other companies did not respond to requests for comment right away.
When it launches a new framework for targeting advertisements without the use of so-called “cookies,” Google has promised not to monitor individual online activity.
The commonly used Chrome browser from Google has recently begun testing an approach to monitoring that it claims will enhance online privacy while still allowing marketers to serve up relevant ads.