No. When you create a shared link to content a url is created which will work until the link expires. The expiration date of the link can be set and adjusted by you the owner of the content at any time. You may also choose to no longer share a link at anytime. So if you provide the url to someone and realize that it was a mistake, you may unshare that url at any point.
For example, I may share a folder and choose that the URL expires in 2 weeks. If after a day I change my mind and would like to make the content available for a month I may adjust the expiration date to be one month in the future and the url would remain unchanged.
Amazon provides information on the SLA for the underlying S3 service at the following url.
Amazon aims for 99.9% uptime for their S3 service. This is also the goal we shoot for and have achieved for our website and supporting services to date. This translates into about 9 hours of downtime per year. If for some reason you are unhappy with the service availability of S3 or AtomicDrive, you are welcome to cancel your subscription at anytime.
The following url describes Amazon's process for handling non-payment.
Essentially, Amazon will attempt to collect payment for services 4 times with each attempt being about a week apart and will send notices that they were unable to charge your account and you should update your credit card information with them.
If at the end of this process they are still unable to collect, your account will be cancelled and your authentication credentials will no longer work.
There should be no assumptions made about the duration of time which your data will be retained after cancellation. If you change your mind and resubsribe after a day your data may or may not be available.
You retain all rights, title and interest including intellectual property and proprietary rights in any content that it yours! Uploading content to AtomicDrive in no way gives us nor Amazon any owning interest or right to the content which is uploaded. It is yours period!
The following url contains the license agreement for S3.
10.2. Your Applications, Data and Content. Other than the rights and interests expressly set forth in this Agreement, and excluding Amazon Properties and works derived from Amazon Properties, you reserve all right, title and interest (including all intellectual property and proprietary rights) in and to Your Content. We will not disclose Your Content, except: (i) if you expressly authorize us to do in connection with your use of the Services; or (ii) as necessary to provide the Services to you, or to comply with the Agreement or the request of a governmental or regulatory body, subpoenas or court orders.