I am not categorising metal implements of any sort- I am just trying to explain concisely without any sarcasm or other meaning that these days any sharp metallic objects are likely to receive unsympathetic treatment in an aviation environment. To need to take needles away these days, one should always have a letter. As a Captain of an aeroplane, I have had nailclippers, not scissor type but the squeeze together ones, removed from my briefcase washbag! One imagines Ali the Terrorist, bursting onto the flight deck, and spying sticking out of the Captain's bag, a nailclipper! With a whoop of satisfaction, he grabs down and holds them out threatening the pilots with imminent injury as he holds the nail clippers opening and closing like a shark's mouth!
What chance with such logic pervading security these days does a syringe have? It's not the airline, it's security.