If your Feedback campaign collects Personal Data from your users, then you need to have explicit consent from them to send this data to Mouseflow. This is required under Mouseflow's and also under the privacy regulation in Europe (GDPR).
Personal Data is any data that could potentially identify a specific individual. Any information that can be used to distinguish one person from another and can be used for de-anonymizing anonymous data can be considered Personal Data.
Names and addresses
Financial Information (PIFI)
Unique Identifiers (like a passport or social security numbers)
This list is not exhaustive. You can find more information here. If you have any questions on GDPR, try looking over our Frequently Asked Questions on GDPR.