https://www.pcgamer.com/oops-blizzard-accidentally-made-symmetra-the-most-powerful-character-in-overwatch/

Symmetra's long-awaited rework went live on the Overwatch PTR earlier this week, but in the days since, an exploit has been discovered that lets the newly redesigned hero pump out massive damage. Her reworked kit is meant to deal more damage than before, but the exploit lets her rip through enemy heroes in a fraction of a second. 

Here's how it works: Symmetra's beam is intended to be held down, dealing damage over time at a set interval. But by rapidly activating the beam, you can trigger its initial damage faster than it would tick by holding it down. The exploit requires the use of a rapid-keypress macro, which is a bannable offense, but that hasn't stopped some players from testing just how much damage the new Symmetra could potentially pump out if this goes unfixed.