The potential ladies will also have to undergo a test involving jiggling and jogging to determine their breasts' authenticityI am 100% certain the only concern here is historical accuracy. After all, it's common knowledge that silicone implants of this nature weren't used before 1962.
The obvious joke here is "I wish I was the casting director!" I believe that's a bit shortsighted. What if you're not sure about someone? What if an actress misreads the look on your face and accuses you of suspecting something? What if she's not misreading your face? It's a scenario where you'd potentially have hundreds, if not thousands, of attractive young women knowing for certain that you're staring at their chests and judging their authenticity. The hostility generated could power all of LA.
...Okay, yeah, I'd still totally take the job. I'm only human, after all.
In all seriousness, while I was made aware of this via TVGuide.com, there are a lot more details in the original source of this information, The New York Post. It's actually somewhat disturbing what they went through to "enhance" Keira Knightley. I'm sure she would have been just fine without it.