People love the cloud nowadays, dropbox, google drive and so many more.
Many of these encrypt your files, but they maintain the keys, and if someone gets ahold of your account information they can download your data or access it. Leaving it vulnerable. Especially important for example Lawyers who require security and privacy for there information. It could just be for your own piece of mind.
A really awesome solution to this is Boxcryptor which encrypts your data seperately from any of those cloud services. Essentially giving it 2 sets of encryption. And if someone were to get access to your cloud account they would still not be able to access information you chose to encrypt with boxcryptor. With boxcryptor you can choose to encrypt all or some of your files in which ever cloud drives you choose. Most common cloud drives are supported.
There is a free version and a paid version so give it a shot and try it out.