I'm not sure why he put that in the ROM, if you touch it, it will lock your screen. Basically the same as turning off your screen (depending on how you have your phone set up). You can get rid of it using the HD Tweaks app. Well, it was an option on previous HD realeases, I did a quick scan and I'm not seeing it. It may be buried in one of the sub menus. If I find it or you find, post the path in here.
Found it. In Hyperdrive Tweaks App <Statusbar> scroll down to <Statusbar Icons> it is the <Enable Lock Button>. I had to check it and then uncheck it and the lock went away.