screen scrape MLB betting lines

[SumZero]

If I wanted to write a program to shadow bet throughout the mlb season, and wanted to get real betting lines into it in an automated fasion, what sites would you recommend? Preference is for a site that:

1. has real lines with real betting behind it
2. gives lines on both the win/lose game and over/under runs scored for mlb
3. has these lines published somewhere you can get at without a lot of signing in and redirection
4. doesn't explicitly and specifically forbid this type of behavior