Does Google automatically penalize sites found to be doing blackhat?

Does Google automatically penalize sites found to be doing blackhat?

I've heard that the penalty for sites doing blackhat might not be as obvious as an automatic drop in rankings.

Google is very subtle when they are deranking most sites, so as to sabatage blackhat users, so they don't really know what techniques are/aren't working. Sometimes, they let a site stay on top for a period of time, after it's discovered they are using a blackhat techniques and then let it slip in rankings and rebound a little. This see-saw motion in search engines confuses the person who is using the blackhat techniques, so they're not sure what move to make next.

And, this is done over days or weeks, so the person using illegal blackhat techniques has to guess at what is working and what is not. And, then Google simply pushes that site to the bottom of the rankings when it's ready.