Good question, I'm glad you asked!
Once a survey has been published and has gotten responses you can choose whether or not to share your data by creating a response URL that you can then give to others. The option is automatically set to "No," so that there is no survey response URL. This can be changed from within the account by clicking on "No" and switching it to "Yes" which will create the URL, as seen in the following screenshots:
Constant Contact takes the privacy of our customer's information very seriously, and so we would not share your survey responses with any other parties or provide a way for people to access it other than by the response URL which you would have to personally create and share.
I hope that helps to answer your question, but please let us know if you have any further inquiries!