The Y2K bug, also known as the Y2K problem or Year 2000 Problem, was a major perceived threat of the late 1990s. The Y2K Scare was a phenomenon at the turn of the 21st century where computer users and programmers feared that computers would stop working on December 31, 1999.
The UK exiting the EU, also known as Brexit problem, is a major perceived threat today. The Brexit Scare is a populists phenomenon of this century where political formations, economic establishments and the population fear that the UK as we now know it would and could be badly damaged come exit.