If you use an unpaid dropbox account, be very careful. The support demands currently exceed supply and you are unlikely to get any help.
Dropbox Support, Feb 19 12:18 am (PST):
Thank you for your support request. Recently, we have been receiving a high volume of support requests and haven't been able to get back to you within a reasonable amount of time.
The volume of inquiries we receive on a daily basis prevents us from responding to all requests. Although requests from Pro and Teams users will be given priority assistance, we will do our best to get back to other inquiries when possible. If you are not a Pro or Teams user and you're looking to resolve your issue before we can respond, you may want to check out:
If you need to restore a large number of files and are unable to do so, please visit the following instructions to help us speed up the restoration for you:
If you are still experiencing problems, please reply to this message. We will try our best to get back to you, however we cannot guarantee a response. We're very sorry for the inconvenience.
The Dropbox Support Team
We use Dropbox a lot and this is a worry for us.