Definition Of Cloud Computing (in me own words :D)...
The process of managing data (accessing and processing) online using remote computers/servers on the internet.So in this sense, even something that is as small as an e-mail account is actually a derivative of a cloud. For instance, when making e-mails, we sometimes use attachments that are stored in your local HDD and upload them to the online mail service and edit them within their servers + all those typing etc are also a way of processing data online, right?... so we've been doing this for a long time. Anyway...
|Shi*... I knew it!.|
1. Who's in control of your data?
For instance, some may even be surprised to know that when you use a cloud computing service, your data, not only they're stored different locations but those locations can be "as far as" different countries.
So, there could be occasions such as the restrictions that apply to your data within your country (who can access the data etc) may no longer be valid as long as your "cloud" is stored in another country!. So, always ask questions about the liability of your data concerning these types of security issues.
2. How good is your Cloud Service provider's security?
On a cloud, even the data is stored within a single country, a given data is always (not necessarily always, but usually it is) on the "move" from one location to the other. So if the service provider has a weaker security levels this gives people like bad hackers (there are certainly good ones too :D )the ability to steam your data while on the move. So take extra precautions about the levels of the security of your service provider and how reliable they are.
3. Third-party access?
Sometimes when you join a cloud (especially those free ones) although the provider won't tell you much about it ... some third parties can access certain amount of data about you or your data (such as with a certain Amazon program). Always make sure your personal information + data stored in the cloud storage are only accessible by you.
4. Wanna get yourself locked?
Say due to a hacker attack concerning your account in the cloud ... as a security precaution the service provider may decide to lock your account ... even as long as for few days!. Not to say the impact of this on your business. So ask about them in such as situation what are the safety precautions or how fast they can "unlock" your data??, etc.
5. Bandwidth of the service provider?
This is another major concern. With a cloud storage or computing in general, involves a lot of bandwidth, a lot of it. So it's a must that the service provider has a guarantee that they'll always have the ability to give you a full throttle of data-bandwidth no matter what!. For instance, what's the use of a cloud even if you have the fastest internet connection but the service provider cannot match with you or their servers are usually "busy" :(.
Although cloud computing does has its benefits but if you're not careful while choosing a service provider, those benefits won't necessarily flow at your direction. Hope this was helpful. If interested, Wikipedia has a long, a painfully long article on the subject :P.
I personally would do anything to keep my "cloud needs" at a minimum, but that's just me.