One week their hair grazes their shoulders, and the next it's 6 inches longer.

Extensions have let celebrities change their looks as often as they change their clothes, and it seems this trend has trickled down to everyday life.

There has been a 28.5 percent increase in salons that offer extensions, according to a 2013 study by the Professional Beauty Association. And, as The Cut notes, so is the number of hair extension theft.

Instead of holding up a store, it's the hair that people find more valuable. The hair comes from India, and it is either virgin hair, which means it has never been bleached, dyed or permed, or Remy hair, which comes from one person and is then colored.

At a Chicago store, $230,000 worth of extensions were stolen. In St. Louis, it was $100,000 worth, and $50,000 was taken from one store in Houston. Stolen hair can't be tracked so it can easily be sold, unlike electronics or luxury bags.

"It's the Remy hair that thieves want to get their hands on," according to The Cut. "In order to be good quality, the cuticles must face the same direction and be the same length to avoid tangling. A pack of the stuff starts out at about $100, and a buyer can wind up paying up to a thousand for multiple packs of hair."

And there are people who try pass off inferior hair as the real deal, which is why extension thieves target salons. The owners will have already done the work and found the best quality hair.