If you have information in “the cloud” instead of on your personal computer, there is a dark side that you should be aware of.
The information that you save to the cloud resides on servers elsewhere, such as California or Korea or Canada. Wherever those servers reside, there are laws that govern them and the corporation that controls them. These laws may permit access to that information that is much looser than where you are.
Even within the United States, there is a big difference between the data stored on your personal computer or laptop and the information stored on external servers. The United States government must get a warrant signed by a judge before searching your home (and home computer); however, a warrant is not necessary to get a corporation such as an Internet Service Provider (ISP) or others to give the police your data. Companies such as Google and others can be forced to give the police data without notifying you.
This data is not just on the servers, but can also be found on backup tapes as well. Some services – either by their nature or by design – will keep multiple versions of your data, so all past versions can be scanned.
Cloud computing can be brought in-house to some extent, most notably by using open source projects such as eyeOS (which provides a remote desktop). If you are truly concerned by leaving your data open, do not use unsecured network protocols, and do not set up a server with a hosting service: you must run your own server internally.
Other services will provide a key which encrypts the data on their servers – such that the hosting service cannot read any of your data. These are the best services to use, although they may be harder to find. The most likely cloud computing services to do this are backup services as well as those specializing in privacy.
There is also the possibility of losing all of your data due to a site shutting down. Some sites, polished though they may be, are run by individuals or tiny companies; thus one should not rely on cloud computing alone. Backups should be replicated internally – including backups of all data stored externally.
One good example of this would be the service Magnolia – the service suffered a total data loss stemming from a disaster that took place in February.
Thus, like RAID, cloud computing alone is not a backup!