The internet is officially broken. Well, at least kind of. If you look at the internet for what it is -- a network of destinations that is connected by links -- then the internet really is kind of broken. You've likely arrived here because, all of a sudden, download links for Fileserve, Filesonic, Filejungle, Uploadstation and x7.to suddenly stopped working and you want to know what happened to all of these popular file download services and their not-working download links... well, here it is:
All these cyberlocker services / filehosters effectively killed themselves off, voluntarily no less. Think of it as a mass digital suicide, or self-neutering for download services, however you want to look at it.
Megaupload Takedown Fallout
On January 19th, the US Government took down Megaupload with a massive, worldwide effort. Here it is only a few days later, and all of a sudden most of today's popular file lockers have willingly destroyed their own services as a result.
Why can't I download files anymore?
The simple answer is that most of these now-effectively-dead filehosters have disallowed shared or third-party file downloads. In other words, in order to download a file from Fileserve, Filesonic, Uploadstation or Filejungle, you have to be the person who uploaded the file. It's insane, but this is the way it is: you can only download files that you personally uploaded.
This effectively nulls the millions of links on the internet that point to these filhosting / file download services. Which, by millions, I'm including Megaupload's now-defunct download links...
What about my premium account?
If you currently have (had...) a Fileserve, Filesonic, Uploadstation or Filejungle premium account, your first line of action should be to ask these services for a refund, especially if you recently purchased a premium account. Be prepared to wait a couple of days, though; I'd imagine that these filehosters' email inboxes are being bombarded with refund requests alongside the obligatory, and well-deserved mass-flooding of hate mails.
If you receive a less-than-favorable response to your premium account refund request, or no response at all, then you might consider trying to reverse or charge back the payment for the premium account. Obviously, you should only take this route if you were royally screwed and didn't get to really use what you paid for. Most payment options (PayPal, credit cards) allow buyers to dispute a payment 30-90 days after the date of purchase.
Why did this happen?
My guess, which is a pretty good guess, is that these cyberlockers killed off their services in an attempt to avoid serious charges and prosecution, very much like what happened with Megaupload. In basic terms, the owners/operators of these premium download services are scared -- scared enough to kill off their cash cows in hopes of avoiding prosecution, fines and likely jail or prison time.
Are premium accounts safe now?
For single filehosters: probably not, at least for the moment. Owners of digital locker services like Filesonic, Fileserve, Uploadstation and Filejungle are likely scared and are probably weighing their options to keep themselves safe from US prosecution. Some services may move out of the USA entirely, which is exceptionally smart, some may ban US IP addresses from accessing their services (like Uploaded.to did), some may kill off their affiliate programs, which means fewer download links for premium account members, or some services may decide to close their doors entirely like x7.to.
If you like the idea of having a premium account, which I do as well as countless others, I would highly recommend against buying a premium account from a single filehoster. However, despite the recent loss of 8+ of today's most popular file download services, I would still recommend using a multihoster like Zevera. While Leechpack is another popular multihoster, they are based in the United States, and their long-term viability, in my mind, is questionable so long as they choose to stay in the USA. Because Zevera is international, I think their premium download services are a much safer alternative to US-based services, and certainly a better value when, at least right now, you have no idea whether a particular individual cyberlocker will keep their doors open any longer.
Alternatives to Fileserve, Filesonic and other digital locker services
The good-ish news about all of this is that file download services will continue to exist. Just like the rise and fall of Rapidshare and Hotfile, new services will spring up to replace the fallen Uploadstations, Filejungles and Fileserves of today.
If you're looking for free download services to replace the likes the recently-fallen filehosters, I recommend checking out this Megaupload alternatives page. If you want better access to fast, direct downloads but don't want to risk buying a premium account with a single filehoster, I recommend checking out Zevera's download services.