Selected answers from the Dumb SEO Questions Facebook & G+ community.
Steve Gerencser: I don`t think I ever asked that in 20 years of doing this so I have no idea 😀
Jeremy L. Knauff: You can, but you risk a penalty. Not doing it helps to ensure a more natural link profile.
Tina Willis: My opinion is that not asking for specific text could create a greater risk bc those who are less informed might think they are helping by using very targeted keywords. Of course, I have only asked a couple of times anyway. But that was my thinking at the time.