Worried about who has access to your Mac and its files? While there are several software solutions to this conundrum, here's a novel, potentially fool-proof hardware answer. WARNING: performing this on your MacBook will VOID THE WARRANTY. DO NOT ATTEMPT THIS unless you have an exceptionally steady hand and a very high "geek quotient."

That said, click on any of the images to get a better look, if necessary.

STEP 1: Cut a hole in the casing on the right as shown below. A high-speed precision drill like a "Dremel," using a cutting attachment, is best for this task.

STEP 2: Take out your FI Unit. The one shown below is a Sony "Puppy FIU-600," available at several online sources for around $86.00 USD.

STEP 3: Add a plastic cover over the FI Unit to avoid potentially fatal short-circuiting.

STEP 4: Carefully solder the FI Unit into the DC-IN Board as shown.

STEP 5: Close the casing and admire your handiwork.