I dont know what you need for proof that coyotes have been attacking people, but I have heard of several incidents around where I live.

This happened in the fall/winter just last year. A man was out walking his dog, dog saw coyote and chased it. Man chased after his dog and was bit by a different coyote. I cant find the article but ill keep looking. This stuff isnt BS. It happens.
also:
9 yr. old boy gets attacked.
http://www.thedenverchannel.com/news...75/detail.html