Hacker News on 19 May 2018

• A Wikipedia editor's long-running campaign
• How I targeted the Reddit CEO with Facebook ads to get an interview at Reddit
• Estonia plans to become a free public transport nation
• How to disappear from the internet
• Libui: a portable GUI library for C
• How Judea Pearl Became One of AI's Sharpest Critics
• Lessons from My Math Degree That Have Nothing to Do with Math
• Devices Which Track Cellphones, Intercept Calls Found All Over DC, MD, VA
• Fridge 0.1
• A relatively simple Datalog engine