You may want to delete a link after sharing so it is non-functional. You can set expiration dates when you create any link, but you may also delete them after the fact.
Go to your personal Account Settings in the upper navigation bar.
Click on one of the Manage Links options on the left.
Here you can manage all past links created, and review any reports you have ordered.
Click on Trash icon to the right of any link that needs to be deleted and hit OK. Warning, this cannot be undone.