Hacker News on 21 December 2016

• Cat-proofing a cat feeding machine
• Update on Multi-Process Firefox
• UK Government is breaking the law by collecting everyone's internet data
• Bootstrap 4 drops IE9 support and goes full flexbox
• Four years with Rust
• How Skype fixes security vulnerabilities
• Why Are Ultrasound Machines So Expensive?
• Why I Only Work Remotely
• The Long-Term Jobs Killer Is Not China, It’s Automation
• A Git catastrophe cleaned up