You cannot take pictures here.
Have you ever been told this while trying to make a photo of a friend in a museum, a shop, or an office? More likely than not, you were bullied.
Andrew Kantor's Legal Rights of Photographers is a very nice summary of everything you need to know about law and photos. And it turns out, you can take pictures pretty much anywhere you damn want, and also, you can publish pretty much all of these photos.
Must read for anyone who owns a camera - and who doesn't?