Q: My Upper East Side co-op building takes pictures of all visitors, asks them for identification and stores their personal information in a database. The doorman said this was the superintendent’s idea and the super has access to the files. Please tell me if it is legal to take pictures of my guests, and to log their information on a database?

A: Visit an office building and there’s a good chance the person at the security desk will ask for identification, type the information into a computer and then hastily photograph you with a webcam. Off you go to the elevator banks with that grainy (and invariably unflattering) head shot affixed to a name tag that lets everyone know that you don’t belong.

In some ways, a co-op is similar to an office building. Visitors come through, and management wants to know who they are. “There is nothing inherently illegal with requiring someone to register and have his or her photo taken,” said Lisa A. Smith, a real estate lawyer and a partner in the New York office of the law firm Smith, Gambrell & Russell. None of us have much privacy in common areas anyway, since security cameras are commonplace, and building management can view that footage.

The policy may be intended to add another layer of security, but a co-op is also your home and who wants to make Aunt Gertrude go through the mill when she comes for her weekly visit?