There are _some_ cloud accounts for linux such as Ubuntu One, which I would fear could have similar identification capabilities if ever forced by to do so by a 3-letter agency

Any sort of online service you're logged into is going to have your IP and account correlated with a timestamp. Dropbox, GDrive, and even your e-mail provider. While a device identifier might be more useful it's not like the lack a device ID will keep you from being tracked.