Instructions - Press the green flag, then press 2. With a very simple 5 lines of code scratch is dead. You can not press any buttons on the page. You can not refresh the page. You can not press the back arrow on the page. Scratch is dead, and all you can do is close the page, then re-open it.
Credits - myself. This took about 4 minutes to make. As simple as this is, this is enough to break scratch. If you use this in a project, give credit for 5 lines of code? That's like giving credit to someone each time you use the when flag clicked block. Credit is optional. Just please paste the project link in the description, because I would like to see what... interesting games use this code.