Bias? What bias?

There’s no secret about which party is preferred by the mainstream media:

MSNBC.com identified 144 journalists who made political contributions from 2004 through the start of the 2008 campaign, according to the public records of the Federal Election Commission. Most of the newsroom checkbooks leaned to the left: 125 journalists gave to Democrats and liberal causes. Only 17 gave to Republicans.

I always wonder how that famous training to be objective works. Do they all wear a shock collar in J-school that zaps them every time they express an opinion? And how long does the objectivity training last? Do they ever take refresher courses?