In the original days of the Internet, domain registrations did not auto-renew. This meant that at the end of your year, you had to remember to renew it manually or face losing the domain to someone else. This was especially bad when you had a popular domain, as hijackers would just wait for you to make a mistake and swoop in and steal the domain away from you. I lost my personal domain name years ago to exactly this type of mistake.
Luckily, in modern times, this is no longer an issue. All domain registrars offer auto-renewals and, for that matter, turn the option on by default. Unless you actively disable the option, or cancel you credit card or close your bank account, your domains will continue to renew for as long as you let them. This is a good thing, as it prevents hijackers from taking ownership of your domain because of a simple mistake.
This week, however, the federal government proved that if something can be screwed up, they will be the ones to pull it off. The FBI managed to lose one of their primary domains because they simply forgot to renew it. The domain, CIRFU.net, if the domain that they redirect seized domains to prevent further access to the seized materials. This is done with websites dedicated to drugs, child porn, copyright violations and the like. The most famous of those seized domains in recent memory is megaupload.com, which provided access to all sorts of content.
After failing to renew their domain, a black-hat hacker purchased the domain through a GoDaddy auction and turned into a server hosting ads, scams, drugs and porn. This is not an unusual situation in this case, especially not with a domain that is so highly in demand. What is unusual, in this case, is that it affects every domain that the FBI has seized. All of them point to this single server, meaning that every seizer domain began hosting this content.
As of right now, CIRFU.net is returning a domain error and related domains are now returning a Bing search, meaning that the domains cannot be reached and the browser's natural search feature is kicking in instead. It will be interesting to see if the FBI seizes their own domain back, if they switch to another, or if they have another plan up their sleeves.