Why is American Airlines gathering written dossiers on fliers' friends?

Last week on a trip from London to the US, American Airlines demanded that I write out a list of the names and addresses of all the friends I would be staying with in the USA. They claimed that this was due to a TSA regulation, but refused to state which regulation required them to gather this information, nor what they would do with it once they'd gathered it. I raised a stink, and was eventually told that I wouldn't have to give them the requested dossier because I was a Platinum AAdvantage Card holder (e.g., because I fly frequently with AA). I have written an open letter to AA asking for details on this -- see the link below for the whole text.

The security officer then handed me a blank piece of paper and said, "Please write down the names and addresses of everyone you're staying with in the USA."

I actually began to write this out when I was brought up short. "Wait a second -- since when does AA compile a written dossier on the names and addresses of my friends? Why are you asking me this? Do you have a privacy policy and a data-retention policy I can inspect prior to this?"

The security officer told me that this was a Transport Security Agency (TSA) regulation. I asked for the name or number of the regulation, its text, and the details of the data-retention and privacy practices in place at AA UK. The security officer wasn't able to answer my questions, and she went to get her supervisor.

After several minutes, her supervisor appeared and said, after introducing himself, "Sir, this is for your own protection."

I think it's pretty hard to argue that making passengers produce written dossiers on their friends' home addresses makes planes in the sky secure. I asked again if this was really a TSA regulation and what AA's privacy and data-retention policies are.

The officer said, "This is a TSA regulation."

I said, "Why didn't I have to provide this information when I flew out of Gatwick on US Air in December then?"

He said, "Well, you know that American Airlines has had some terrible things happen to it in the past."

I asked "So the TSA wrote a special regulation for AA? What is the name of this regulation, and what is your data-retention and privacy policy?"

Link