Here’s the problem: it prevents users’ from using their arrow keys for purposes other than browsing images. This is problematic because the thumb buttons on modern mice navigate backward and forward through browser history by emulating keystrokes (alt/cmd + arrow).
Once a user clicks through to a myspace photo, attempts to traverse backward through browser history by clicking the ‘back’ thumb button prove fruitless. They have to manually click the ‘back’ arrow in their browser. This confuses the user and interrupts her experience.
To make matters worse, some users (myself included) don’t have a ‘back’ arrow in their browser. I removed mine because I became so dependent on Firefox’s keyboard shortcuts I found myself never using the ‘back’/’forward’ buttons. It allows more space for the location bar so I can read longer URLs.
The result is a blackhole. I navigate to a Myspace photo album and can’t exit. I’m forced to open my browser history or right click > ‘back.’ It’s annoying and adds to the aggro Myspace loves to evoke.