From multiple sources, including the Green Bay Press-Gazette and ESPN, among others.
Now, on one hand, you can certainly understand that William Henderson, being a career Packer, has an intense loyalty to the team, and wants to display said loyalty along with many others at Lambeau Field by booing the man that was once considered a deity in Wisconsin.
On the other hand, if we're going to be talking about players booing because a Packer turned free agent signed with the hated rival Minnesota Vikings, William Henderson isn't exactly a great source of credibility.
Isn't this the same William Henderson who, in 2006, came over to Minnesota to sign a contract with the Vikings?
Oh wait, I do believe it is. So let me get this straight, William Henderson... You, someone who spent his entire career with the Vikings, decided that in 2006 you would go to the Vikings and negotiate a contract (Which, of course, did not come to fruition as he's still a Packer)... And now you're basically going to boo someone else for doing the exact same thing?
I guess nobody ever accused Henderson of being smart... Or having a long term memory, for that matter.