Mega site's private link farms - getting away with it?

Researching backlinks from some of the largest/most-heavily trafficked sites, I’ve noticed where some are involved in widespread practices of creating what are obviously their own privately held/managed/directed link pages. These are pages having blatant, lengthly, exclusive lists of links back their own pages. Talking 50 to 100+ links one after the next and some times much greater than this. Some without even the pretense of any textual content.

  • I have thought there were penalties for partaking in this sort of thing.

  • I have also thought that G. at times writes out exceptions for sites of a certain age, past reputation, and other parameters that I’d rather not mention.

What is going on here? Are there rules that only the majority of us have to follow?

Do you have any examples to hand of what you’re talking about here?