Filejacking: How to make a file server from your browser (with HTML5 of course)

This is a vulnerability of HTML5

Back in the days of browser wars, there was a joke: Internet Explorer is the only web browser that makes Internet browse your computer. Through various security flaws, IE was exploitable and allowed for remote code execution that could e.g. steal your sensitive files.
But now the times are different. It's not that easy to exploit current browsers, they