How many sites does it take to be considered a PBN and get penalized?

[AMBTL]

How many sites does it take to be considered a PBN and get penalized?

2, 5, 10 or 30 and more?

Let's assume, a small number of sites (let's say a couple) on the same host with/without private whois and same registry link to the main site.
Is it safe or not? Would it be black hat or not?

 

[paul1129]

With same host and without whois you can get penalized just for two sites.

If you have different hosts and whois protected or named after you friends and family members or co-workers then there is no upper limit.

 

[AMBTL]

What if Cloudflare or another CDN is used? I suppose it wouldn't cloak sufficiently, right?

 

[paul1129]

Still you will need Whois protection.