There is a thread at Reddit on the topic of someone building out a PBN, a private blog network. These are often used to manipulate Google's search results through link schemes. Well, Google's John Mueller commented on the thread saying "Sounds like an interesting plan."
The post reads:
I am going to build some PBN and I am getting this service from some one but I will host all PBNs. I would like to know if:(1) it is easy to host all the sites in one go, I mean like 100 blogs altogether or to have them in batches of 15-20 and have 5 accounts - which is better and why?
(2) if I go with either of the above options, will it be safe to give links to my money site from all these 100 sites?
Google is frequently targeting PBNs and similar tactics.
So be careful with these because Google is always watching.
Forum discussion at Reddit.