The security issue
The discussion was dominated, however, by whether or not Dropbox offers the requisite level of data protection for accountants operating in the UK and registered with the Information Commissioner as data controllers.
Hansa put the case against Dropbox: “Be aware it is not secure and the servers are US based (thus minimal privacy). Their staff can access your files and thus give them to others... It’s great for granny's photos, not for business and very probably breaks data protection rules.”
The final point was rebutted by several contributors. Dropbox is hosted on Amazon’s US-based S3 web servers, which are covered by a safe harbour agreement effectively granting equal status to European Union-based servers under the Data Protection Act. Hansa’s concern went further, and related to provisions within the US Patriot Act that gave government forces the power to demand access to files held on US-based servers; the Switzerland-based Wuala service was suggested as an alternative, along with a few other rivals.
The original thread delved into the issue in great detail. If you do not have the time or inclination to research these issues now, be aware that they are important; some relevant links are collected below if you want to find out more later.