From The City Birder:
Robin had worn her bathing suit under her cycling gear. Lying in the sun, she had placed her cycling gear, which included a sports bra, in a neat pile on the wall. I was eating a plum when I noticed that the tern was slowly waddling over towards her clothes. I watched in disbelief as he grabbed the corner of her bra (must have been a "he") and prepared to make off with it. Robin yelled, "HEY", and grabbed the opposite end of the bra. There was a brief tug-o-war. One might think that Robin's ire would have chased him off, but it didn't. He hung around a few feet from us for about 20 minutes. Eventually he took off and joined some other royals down the beach.
It's fairly unusual to see Royal Terns in NYC, but to see the rare subspecies Sterna maxima fetishi is really special. Unless of course it makes off with your underwear.