What is my responsibility to the client for his data? Is the web application legal?

Question

Personal Information

Good day. Suppose I am an individual who has launched some kind of web application that can hypothetically store data on the server side related to the client's monetary information (accounts, etc.). Also, hypothetically, I could charge a fee for using the app.
The questions are: What responsibility do I have to users for their data? The server can be hacked, personal data leaked. Will accepting the user agreement for the use of the service and ticking "I accept" in case of any problems save me from legal liability? Is it generally possible, from the point of view of the law, to accept funds from users, if I am an individual, they will not be able to file any complaint, or so far, that the Internet sphere is little controlled?

Answer 1

Read FZ-152