A consumer rights campaign group has called for a US government investigation into AOL's recent release of customer search data.
Filing a complaint with the Federal Trade Commission (FTC) on Monday, the Electronic Frontier Foundation said AOL should be ordered to reveal more details about its publication of 650,000 users' search queries on the web.
AOL apologised for the move last week after receiving widespread criticism that it had breached customers' privacy. However, the search requests were publicly accessible for 10 days before their removal and continue to circulate on the web.
The Electronic Frontier Foundation said it had submitted evidence that some queries could be tied to individual AOL subscribers, despite the fact that AOL released them without users' names.
It said the data included 175 searches containing Social Security numbers, which could raise the possibility of identity theft.
The group called for AOL to notify customers affected by the disclosure and to stop logging search data "except where absolutely necessary".
"Search terms can expose the most intimate details of a person's life -- private information about your family problems, your medical history, your financial situation, your political and religious beliefs, your sexual preferences, and much more," said EFF staff attorney Marcia Hofmann.
"At the very least, AOL should notify every customer whose privacy has been jeopardised by the company's careless handling of this incredibly private information, and AOL should not store this kind of data in the future when it doesn't have to."
Last week, The New York Times reported it had tracked down 62-year-old Thelma Arnold based on the search data.