PayPal's website uses encrypted connections to safely process payment information, and their system is designed to detect and prevent fraudulent activities. PayPal also leverages a risk-based authentication model that requires users to verify their identities through multiple means, including multi-factor authentication, security questions, and biometric identification. Furthermore, PayPal encrypts payment data in motion and at rest, and their network system undergoes rigorous vulnerability assessments to detect potential bugs and exploits.