HTTP → HTTPS edit
The purpose of this bot is to convert existing external links on Wikipedia, where ever possible, from HTTP to HTTP Secure (HTTPS), i.e. from an unencrypted to an encrypted transportion protocol. There are three reasons for using HTTPS: (i) data is sealed from eavesdropping on the internet cable (privacy) which also prevents censorship, (ii) data cannot be manipulated (integrity), and (iii) data came from the correct source (authentication). Rather than further elaborating (but have a look here), here are some news reports emphasizing the importance of each point.