you don't watermark your photos?
these are fairly high res. no reason not to-even something small and transparent in the corner would work.
as i recall, you want to be a professional photographer. posting these around with no watermark indirectly/directly takes away from future demand for photography services.
its unfortunate, but most people think everything on the internet is free to use for whatever they want, and most artists aren't going to go through the hassle of a lawsuit even if they do somehow discover someone using their work. a little copyright symbol and your name or website would solve most potential problems.