That's the thing. At some point tiny text is mentioned as well, how many times, on a forum, has a person (myself included) used that text to describe an action? At the moment, it seems like they are going for the obvious lot, meta detail stuffing, invisible text, small text and of course, links built.
Entrapment, that's a fine line (IMHO), I have seen a lot of members on different forums panic when their rankings drop and then try harder to get their site back where it was originally. If broadening your link building campaign constitutes as spam after they have toggled your rankings, ouch. Then again, its a well known technique used by spammers. They just crank their software up a notch and hey presto, more backlinks.
Here's a question though.

Why even bother telling people about new updates, algos, and the new patents, what they do,
how they work and then once again point to how to build organic links. If they really wanted to stop spam, they wouldn't give them all the information they needed to find ways around it all.