Write a Python program that implements a sign-up form for a user account. The program should prompt the user to enter their first name, last name, username, password, and confirm the password. It should validate the user input according to the following criteria: 1. The passwords entered should match each other. 2. The password must be at least 8 characters long. 3. The password must contain at least one lowercase letter, one uppercase letter, one digit, and one special character from the set !@#$%^&*()_+=- []{};':\\"\\\\[