Shepherd - 6:20 pm on Jun 12, 2013 (gmt 0)
There are also quite shady SEO tactics where webmasters get asked to remove links by unrelated entities.
I can't believe how link building has morphed into this monster.
Evolution of the link:
1. links freely given as citations
2. trade links
3. beg for links
4. spam for links
5. buy links
6. hack links
7. beg to have links removed
8. buy spammy links pointed at your competitors
9. ask to have your competitors good links removed