Time Warner's internet arm, AOL, formerly America Online, released details of Internet searches performed on its systems over a period of three months by hundreds of thousands of its subscribers, but later apologized.

The data was made open to the public inadvertently Monday morning, apparently posted for research purposes on its website, research.aol.com. Intended for researchers only, the company took the link down after it realized anyone could access it.

Later in the afternoon, the company issued a formal apology, admitting its blunder, and re-stated the projects rightful intentions.

This was a screw-up, and we're angry and upset about it. It was an innocent enough attempt to reach out to the academic community with new research tools, but it was obviously not appropriately vetted, and if it had been, it would have been stopped in an instant, AOL said in a statement.

The data comprised about 19 million Web searches performed by 658,000 users from March through May, but the company reassured the public that no personally identifiable information was released.

Although there was no personally identifiable data linked to these accounts, we're absolutely not defending this. It was a mistake, and we apologize. We've launched an internal investigation into what happened, and we are taking steps to ensure that this type of thing never happens again.