I’ve found a serious bug in the Hub web editor. When I hold down the Ctrl key and then move my mouse over a line of code, the editor instantly duplicates the line and places it wherever my cursor is in the text. This happens on hover only, no click, which makes it very easy to inadvertently destroy a file.
To duplicate it, you just go into the editor, place your cursor somewhere, and hold down Ctrl. Trailing the mouse over other lines will have them duplicated at your original cursor position.
Holding a modifier like Ctrl should not do anything normally until something else is pressed or a mouse click is also used. This makes working with standard shortcuts difficult.