This is a very pertinent thread, and a factor I use each draft now that I know the owners in my league (5 years).
Most of them play it straight up, but there are three - a Yankee, a Brave, and a Mariners fan who overvalue their guys every year (the Braves guy took Smoltz and Chipper 1-2 -- in 2003!).
Burned me last year, though, when I grabbed Boone late in the second round because the Mariner fan was lurking behind with two picks at the turn. I should have passed and let the dude have him
p.s. - Hey, Cubsfan7724: we also have a die-hard Cubbie in our midst, and every year he seems to target ... Red Sox players!