When you create an account, create a diagram and save it on the web site, then the text of the diagram is stored until you delete it.
If you do not save the diagram on the web site, then its image is stored for up to five minutes, and then erased.
Diagrams are only shared with people that you send them to. There are two types of links that you can send. The "Link to this image", with the very long links, contain the complete diagram text within the link itself, so a skilled person can decode it given only the link. The "Link to this image (Updates when you save)" are short links that refer to the file. You can revoke this link by deleting the file you saved on websequencediagrams.com.
Access to the diagrams in the database is limited to one employee of Hanov Solutions Inc.