In my case, the back button didn't go back past the root page of the site. It trapped me where I did not want to be. I didn't know about holding the back button down, and I appreciate the tip, but I don't want to need to know it.

The back button not functioning made me:

- feel frustration and distrust

- associate those feelings with the product and its creator

- never want to use the product, despite being interested in it

Clearly, I'm not the only one who felt these kinds of things. It seems to have completely overshadowed the product.

My takeaway is this:

Do not ever alter fundamental UI behaviours of the browser.