I happily use Flickr too, for public viewing of my pics. Unpretentious and a lot of fun.
You can of course keep them private for family, friends, likeminded etc.
I've used a few others, photbox, photobucket, pbase, epz all slightly differing emphasis.
Don't think you can protect from downloading, but worthwhile using a visible copyright if it's bothering. Personally, not being a pro tog, gives me a buzz if downloaded.........just nice to be asked, and credited.