The document discusses JSON injection security concerns. It describes what JSON is and how it is commonly used to transmit structured data between servers and web applications. The main security risks discussed are: (1) using eval() to parse JSON, which can enable JavaScript code injection attacks; (2) sensitive JSON data being stolen through JSON array hacks or CSRF attacks; (3) potential data theft, forgery, or misuse if JSON data is compromised. It provides recommendations for securing applications such as using a JSON parser instead of eval(), validating JSON with regular expressions, making JSON responses non-array objects, and only allowing JSON data requests via POST. Examples of past exploits exploiting JSON vulnerabilities at Gmail and Twitter are also briefly mentioned