I don't for a minute believe Harbaugh gives a rats ass if they dope. He played in the NFL for a long time and knows what goes on. This is just Harbaugh keeping a media story going and causing a headache for Seattle. Well played, I say.
I love Harbaugh but he's just playing to the media here, he knows damn well he has players on his own team who use performance enhancers, EVERY coach knows that. they might not know all the specific players but they're not stupid they know guys use PED's in the NFL.
With Seattle it just seems like right now it might be "systemic", in that it might not be as simple as rogue players doing it on their own. Afterall USC had similar issues when Carroll was there, they even had kids who barely played who were doing and dealing steroids when he was the coach.