The Cloud is a powerful tool for sharing, it can enable people and organizations to be far more productive, especially in today's global and telecommuting age. However, Cloud providers can make it too easy to share data, as such organizations and their employees need to be aware of these risks.
Dropbox (the 800 pound Cloud gorilla) announced last week a new feature, when you share a folder you can allow those you are sharing with to invite others. In other words, you can give others admin control of your shared folder. What they don't tell you in the announcement is this is now the default feature. It also retro-actively applies to any shares you have created in the past. In other words if you have ten folders you have shared in the past, you need to go into your settings and disable this new feature in every folder you have shared, then go back and enable it for only the folders that require it (hopefully none).
The challenge with the Cloud, SocialNetworking sites and other online providers is that they have a business need for as many people as possible to be sharing as much as possible. The more people that share the faster the companys' businesses can grow (think Facebook). This drive for sharing can expose organizations and people to a great deal of risk. As always, just a little bit of awareness can go a long way. If you are looking to educate your employees about the risks of using the Cloud, check out the OUCH! security awareness newsletter.