tweepy/tweepy — pull request #149 by coderholic (2012-02-29 18:16:11+00:00)
Title: lookup users API call doesn't require authentication. 

See the documentation at https://dev.twitter.com/docs/api/1/get/users/lookup and try the example: https://api.twitter.com/1/users/lookup.json?screen_name=twitterapi&include_entities=true