It wouldn't even take a computer or any kind of theft. Physical forms are available in truckstops. Somebody could fill it out, make up a doctor's name and turn it in. It wouldn't be an issue until there was a serious accident. When ever I've handed my card to a DOT officer they barely even look at it. The registry should help to cut down on this type of fraud.
Yes, it will, but at the expense [literally!] of those of us who never cheated. And the potential for abuse shifts to the medical providers, who are far better at it than we could ever hope to be.
Example: providers who own [or have heavy investments in] sleep testing centers - might they diagnose 'possible' sleep apnea that requires testing more than those who have no ulterior motive?