Thanks to the good old EU and it’s charming directives, UK law now requires websites to show a warning to the user if they are using cookies. This is the Privacy and Electronic Communications Regulations (PECR), and there’s specific cookie info here.
Let’s lay aside the fact that this is incredibly tedious for the user, who either already knows that almost all sites use cookies, or else doesn’t know what a cookie is and probably doesn’t care.
If you’re a developer having to implement this, I’ve found a superbly easy to use and quick to implement Cookie Law compliance solution. You just follow a little wizard which generates a snippet of Javascript that you paste into the <head> section of the page, and you’re done. No downloads, no faffing about. It probably couldn’t get any easier!
https://silktide.com/tools/cookie-consent/download/
Hats off to them for a job well done! (This isn’t a paid endorsement, by the way!)