Dropbox just did a crappy thing to its “Basic” users—free users, that is. The company quietly added a new caveat that limits these accounts to a mere three devices. To use your Dropbox account on four or more devices, you must pay for the service’s premium version, which will cost you at least $9.99 per month or…
Source: LifeHacker – How to Unlink Dropbox Devices to Meet the New Limits for Free Users