911 is the go-to number for most people when there’s an emergency. But 911 is an old system and old systems are often vulnerable to distributed denial of service attacks:
For over 12 hours in late October, 911 lines across the country were ringing so much that they nearly went down. Nobody knew why this was happening, until Phoenix police discovered that 18-year-old Meetkumar Hitesbhai Desai tweeted a link that caused iPhones to repeatedly dial 911. Now, more details have emerged about how the Twitter prank spiraled out of control.
The lessons to take away from this story are don’t to click random links and have a backup plan in case 911 is overwhelmed.