Switch your display to greyscale. Disable javascript in your browser. When someone sends you a meme, instead of clicking X to dismiss the facebook login popup and see the public page, reply "sorry, I don't have facebook". Become insufferable.
One of them even was browsing many webpages using a command line based browser rather than just using something like Firefox.
As a non dinosaur, It's not actually hard nor tedious to not use JavaScript everywhere and I would recommend it. I think the problem in your situation may have been that those people actively made their problem your problem.
Never send facebook links, problem solved. It's poor form.
The little "X" you refer to is rarely there for those of us who don't ever log in.