Federal law prohibits harassment of owls. Harassment is to disturb. Disturb is to interfere with. I would think that using mice to lure Snowy Owls close for photographs is interfering with the bird's usual behavior. In that case, baiting owls is against the law.
And baiting owls is a cheesy way to get a photo. Don't those photographers -- and more than one has been baiting owls seen in the town of Ramsey and in Dakota County -- don't they have any pride?