Christopher Meloni and Hilary Duff

A new trend is making us jumpy — shark jumpy, that is: Young, hot musicians going for acting cred by guest-starring on gritty procedurals.

First Taylor Swift guested on CSI. Then Ashlee Simpson and Pete Wentz appeared on CSI: NY. Now, Hilary Duff is joining NBC's Law & Order: Special Victims Unit (Tuesday, 10 pm/ET). Duff has aimed for acting cred before, playing an oversexed popstar in the movie War, Inc., but no one saw it. Now on SVU, she's playing an irresponsible young mother who becomes a suspect in her daughter's disappearance. Really? It was hard enough for us to buy her as the heroine in A Cinderella Story, and that part was made for her.

We understand that guest stars are important to series, and that the bigger the name, the better the ratings. With procedurals, the more salacious the crime, the bigger the buzz for the show and guest star. But does seeing such recognizable stars — and ones not known for dramatic acting — take you out of the story?