One of the many buzzwords in technology today is "bring your own device" or BYOD. This term gets a lot of play in the industry primarily because businesses are not providing the kind of technology tools that professionals need to be highly productive. Today's technology professionals are enabled via their tools and if they are given substandard tools, they are more than happy to provide their own to ensure their productivity is not impacted. Once you begin to use a smart phone or a tablet and you realize the power that they bring to the speed and simplicity of doing your job, you are going to bring yours to work. This same phenomenon is happening with cloud services. We are in the era of "bring your own device" but also "bring your own cloud". If you rely on Dropbox, or Evernote or many of the other consumer cloud services you are not going to put them down during the work day.
The issues caused by "bring your own device" such as lack of control, IT support, information security, regulatory compliance, etc are compounded by the cloud services you use on that device. I have heard from a number of my friends in the security industry that they spend a lot of time finding and uninstalling such services given their lack of enterprise security and privacy, but they have no replacement to offer. The security community cannot accept (nor should it) the use of insecure services, but the use case is so compelling for productivity that people are just going to provide their own. Businesses need to learn that unless they provide comparable functionality from both a device and a cloud service aspect your users are going to bring theirs with them to work, the implications for your sensitive and regulated data not withstanding.