Google cares about its SERPs. Your competitors care about beating you. If you get called out in a popular forum, I think it's bye-bye time.
There are probably thousands of examples of sites getting "called out" ... and nothing happening.
You're kidding yourself if you think Google has a team going through forum posts to find sites on which to impose manual penalties.
If there's an exploit that's working well Google will not and I repeat will not ban an individual site (unless it's a big 'un like BMW or hubpages). They will let the site sit there corrupting the SERPs till they can figure out an algorithmic solution to preventing the "exploit" from working. Sometimes, as with the PageRank manipulation of the 301/302 redirects of expired domains some while ago, it takes years before Google implements an effective algo tweak.
@webgeek is spot on. If you were there at the start, and a player, you'll know that Google resisted dealing with or talking with webmasters. They considered us a nuisance because we were trying to manipulate their results. They absolutely hated us!
Then they had a Eureka moment - you can attract more flies with honey. So they let Googleguy post some comments in webmasterworld.com (the top webmaster forum at the time). He found that he could manipulate what webmasters did by dropping hints as to what Google liked and didn't like.
Some of us called it out as FUD at the time, but the average bloke on the street fell for the BS that Google was interested in helping them rank.
Googleguy then went public, revealed his name as Matt Cutts and started a blog to make that FUD his full time job.
Everything Google pumps out is PR. It's designed to manipulate you, not get you the top rank!
Why?
Because Google was desperate. They relied so heavily on citations and once webmasters realised this weakness they piled into a million different ways of getting links. This made life very difficult at the Gorg! Google "guidelines" are a way of salvaging the signals Google so desperately needs. Follow the guidelines and you're simply helping the Gorg, any benefit to your business is incidental and, probably, going to be shortlived anyway.
Break the "rules" and your rankings will be temporary, you'll eventually lose them in algo tweaks. Follow the rules and your rankings will be temporary, you'll eventually lose them in algo tweaks.
What's the difference?
The difference is that clueless SEOs want a nice easy set of guidelines to follow ... and Google provides those guidelines. The smart SEOs, OTOH, research and experiment and tweak and they work out for themselves the techniques that result in organic traffic.