Aside: if you disagree with this philosophy and do not want GIFs to auto-play, there's a very handy Firefox extension to accomplish just that: https://addons.mozilla.org/en-US/firefox/addon/toggle-animat...
I find it makes reading the web a much more pleasant experience.
Makes it completely unsuitable for many uses of GIF.
Would love to be wrong or out of date on this, so feel free to let me know if I am ;)