A Million Ways to Die on the Web
This is a list of common ways websites shut down and user content gets permanently deleted. If you know of a website exhibiting any of these symptoms, please tell us on IRC.
- This list is very much not complete nor comprehensive.
- The best way to keep your data safe is to make proactive backups.
- The average timespan of warning-to-shutdown is 30 days. Sometimes, there's no warning whatsoever.
- Fortunes can change, websites can suddenly become profitable. Just don't count on it.
- Death can be sudden and happen overnight, or it can be drawn out over years.
- Combo death: A website can go bankrupt and be acquired.
Situation: Company A creates a service or buys out Company B and integrates them with their website. Years and years go by, with updates to the service slowing to a complete stop as employees quit or are reassigned. One day, Company A decides managing it is too expensive and not worth the effort, so they shut it down.
Pushed out by a competitor
Situation: Company A runs a service, maybe with a limited market (country, age group etc.) One day multinational Company B appears, covering Company A's services, and soon more and more users think "why not use that service if so many others do?", and a bit later "why use any other service, if everyone uses that?" Unless company A is lucky enough or finds a way to keep users, it can soon end its business, left by the users.
Exercise: Think of some services you used happily back then, but now even mentioning their name is embarassing. If these services are still active (used by a group of "hardcore" users), it's not too late (but definitely time) to archive them!
Situation: Company A does "Facebook for cats". Company A grows a small community of loyal
cat soldiers users, but doesn't gain enough traction to keep things profitable. Company A can't find anyone who's interested in acquiring them, so they shut down.
Variation: Company B starts a service that becomes very popular in a short time, showing an exponential growth. CEO of Company B (in fact, just Joey in the garage) has no idea of a good business policy, or never even wanted to make it a big business, so as soon as the HDD gets full, he pulls the plug.
Situation: Either Company A releases the new Singing and Dancing Version 2.0 website, which is supposed to succeed nasty old version 1.0, or Company A "pivots" and becomes The All New Shiny Company A. In either case, Company A removes their old website and deletes all of the user data.
Situation: Company A buys Company B, employees and all. Together, they will continue their incredible journey to make the world a better place. A few months/years/seconds later, Company B is dead and its employees are either laid off or reassigned to Company A projects.
Situation: Same as Acquired/Acqui-hired, but the purchasing company is known for suddenly and randomly shutting down websites. Named after Yahoo!, which has a track record of doing this.
The prognosis here is critical. You should make local backups of all of your data ASAP (better yet, why wait until it's too late?)
Situation: The owner dies, a loved one of the owner dies, the owner or the owner's spouse had a baby, the owner is having a divorce or the owner gives up.
Situation: Company censors parts of the website for violating its Terms of Service. The evidence for the removal may not be legit. For example, YouTube used an artificial intelligence algorithm to remove videos sympathetic to terrorist groups like ISIS or al-Qaeda. Videos and entire channels documenting war crimes have been removed because the algorithm falsely identified them to be sympathetic to terrorist groups. 
Situation: Instead of raising a new datacenter one year another, Company keeps deleting old stuff regularly.
Situation: If a user deletes a video from a video hosting site, all of the associated comments would be deleted. If a news article was deleted, all of the associated comments would be deleted. If a user account was deleted, all of the data would be deleted.