I don't understand

Seeing as two people near to my heart are visiting Washington D.C. in the next month, I was having a conversation about the whitehouse and tours with one of them. She pointed out that there is a very strange list of prohibited items if you take a White House tour (which she unfortunately can't because she's a foreign national).

They include:

handbags, book bags, backpacks, purses, food and beverages of any kind, strollers, cameras, video recorders or any type of recording device, tobacco products, personal grooming items (make-up, hair brush or comb, lip or hand lotions, etc.), any pointed objects (pens, knitting needles, etc.), aerosol containers, guns, ammunition, fireworks, electric stun guns, mace, martial arts weapons/devices, or knives of any size

While the weapons certainly make sense, just as the pointed objects and aerosol containers, I'm not sure what kind of damage a hair brush could do. I've seen some bad hairdos, including that oh-so-brief flirtation with backcombing in the 80s, but really, if someone were to backcomb Mr. Pres's hair, they really couldn't make him look any more ridiculous than this.