What is Cloudflare?

[#1]

Has my brower been hijacked?
Which ever i use: Firefox Chrome Opera or IE i keep getting a time-out message and can't connect to the internet.
Error 522 Ray ID: 12d1c874f77c06d0
Connection timed out
And who or what is a Ray iD?
There's also a cloud diagram

[#2]

A lot of sites use it for DDOS protection.

Quote

CloudFlare is a content delivery network and distributed domain name server service marketed as improving website performance and speed and providing security.

I'd have thought it'd only affect certain sites though.

[#3]

As others have said it's a CDN/DNS service.
It works by acting as a proxy between visitors and the real server hosting a website, if the website owner has decided to use Cloudflare static content such as images.etc will get cached on the cloudflare CDN and served from the nearest edge node, thus making the website appear faster and also reducing the bandwidth costs for the site owner.
They also do some request filtering/web application firewalling to provide an additional layer of security for a website and provide some DDOS protection (as usually the attackers will end up hitting cloudflare instead of the actual site)
Usually when you get a cloudflare error page it means that the server that's actually hosting the site itself has gone down for whatever reason and the cloudflare network doesn't have a copy of the content you've requested, if they do have a copy of the content you'll get a cached page along side a message reporting that the site is currently offline.
The ray ID is the node/cluster your request has landed on, they are displayed to help Cloudflare support troubleshoot an issue (E.g if the site operator complains their sites up but cloudfare is saying it's down, providing the Ray ID would make it easier for them to determine which server on their network was presenting the user with the error message)