Trustwave SpiderLabs recently undertook a survey of some 100 popular WordPress plugins for possible SQL Injection vulnerabilities. Some good news is that in the vast majority, no such vulnerabilities were identified. Most plugins were found to be using either prepared statements or suitable sanitization when incorporating user-controlled data in a query.

Secret-Chats in Telegram use end-to-end encryption, which is meant for people who are concerned about the security and privacy of their chat history. The messages can be read only by sender and receiver, and not even Telegram administrators have the encryption keys necessary to read any chats. From the Telegram FAQ.