By Jenn Bernstein

MOORESTOWN, N.J. (CBS) — Eagles quarterback Michael Vick is cancelling his book tour because of death threats against him.

Vick was supposed to sign his autobiography “Finally Free,” at various Barnes and Noble stores in Pennsylvania, Atlanta and New Jersey.

One event was scheduled at the Moorestown, New Jersey location for March 23rd, but the event now reads “Canceled by Publisher” on its website.

In a phone interview, Vick’s spokesman Chris Shigas, said, “there’s been a recent uptick in some of the violent threats through social media, but also credible threats of violence that were phoned into bookstores, threatening Michael Vick, threatening his family, threatening the bookstore’s property, and threatening bookstore employees.”

Shigas said the nature of the threats revolve around the crimes Vick committed.

Before signing with the Eagles in 2009, Vick served 18 months in federal prison for his role in a dog fighting operation.

Vick has tried to repair his image. He’s partnered with The Humane Society to lead an anti-dog fighting campaign.

“Unfortunately some of the behavior is inappropriate and unacceptable. What we have now are a few extremists, who I don’t think represent the animal welfare community,” said Shigas.