While the growing popularity of social media has brought many benefits to society, it has also resulted in privacy and security threats. The authors assessed the security and vulnerability of 50 social media sites. The findings indicate that most sites (a) posted privacy and security policies but only a minority stated clearly their execution of the key security measures; (b) had network information that was publicly available through Internet search, which was vulnerable to cyber intrusion; and (c) were secured with firewalls, filters, or port closures, with only few ports detected as open, which need further improvement.