Screen Sharing with Multiple Monitors

Awhile back, I discovered an even better, simpler, more reliable, and free way to accomplish the goal of screen sharing without people being able to mess with the remote mac or observe you working. All you have to do is:

1. Create a secondary user on the remote mac.
2. Screen share into your account (assuming it's the one that has the screen locked).
3. Use fast user switching to switch accounts to the secondary account
4. Lock the screen of the remote mac using the apple menu -> "Lock Screen" option
5. End the screen sharing session
6. Screen share into your account again (which no longer is showing on the screen of the remote mac).

Viola! You can now work without anyone messing with your keyboard or watching what you're doing. Much more reliable of a method than Shades and free too.

Alright. The issue is a stupid one which is not entirely evident. When setting up a Mac with this many screens, be careful with the arrangement. When arranged all in a row, even a 1 pixel overlap will cause the overlapped screen to take over all of the others and cause the behavior I stated above. It is not evident from the desktop. On a gut feeling I ended up dragging all of the screens around to make sure they were entirely aligned and as far over as possible from the previous screen. It turned out the first screen was the slightest bit overlapping the second.

I'll leave this question/answer up for anyone else who might encounter this bizarre issue.