Scraping a website

We need to scrap from the website [login to view URL] a user's friends and scrap the function of messaging between users. Part of the process to scrap a user's friends from [login to view URL] is to log the user in, which will be done locally on our site for our user. There is some public api I found that may help in this. The functionality of messaging from user to user is on the same page at [login to view URL] as the friends so this should be a domino sort of effort; once you find out how to do the friends the messaging follows suit.