I had the idea that if you use JS cookies and HTML5 localStorage together that it might be possible to create a loop where after permission had been granted to store data a site owner could recreate a cookie from localStorage and vice versa. This is just a proof of concept and might be considered somewhat 'Black Hat'. Think of it like cookie persistence but like really persistent. It was built on a lazy sofa Sunday so probably doesn't work on all browser/platform combos but it definitely works on Mac OS 10.11 and Chrome build 50. YMMV.

If you're thinking of implementing Crumbs on your own site then perhaps you should think carefully at which point you do so. I would certainly only write the initial cookies after the user had clicked to accept. Then this cookie/localStorage Frankenscript wouldn't feel quite so evil. Use your own discretion.

After I started work on this project I realised that it's so obvious that someone must have already implemented it in the wild. That's when I discovered everCookie. It's not quite the same thing but it's got elements of the same sort of thinking.

MIT