AccountEdge Mobile Security
Dropbox is potentially more secure then your own computer. We'll let them tell you: visit Dropbox (https://www.dropbox.com/help/27) for more details.
Dropbox Access Permision Required
No one can access your AccountEdge folder on Dropbox without your permission.
Lost iPad or iPhone
If your iPhone or iPad is lost, you have a couple of choices with regard to your data. You can remove the iPhone or iPad in the devices list in the Manage AccountEdge Mobile window. This will remove the device from your Dropbox account.
Since a single Dropbox account and password is shared for all of your devices, you might want to change your Dropbox password. You can go to www.dropbox.com and change your password and then in AccountEdge use the Reauthorize button on the Manage AccountEdge Mobile to enter the new password. This will leave your data intact in Dropbox.
Using the Unlink feature in the Manage AccountEdge Mobile window removes all AccountEdge data from Dropbox. After Unlinking and possibly changing your Dropbox password, you can re-Link to your Dropbox account and sync.
You might also consider a remote wipe of your device. This can be done using the Find My iPhone feature which allows for remotely wiping and locking the device. Check with the folk in an Apple store near you for details.