Received Complaint about False WHOIS Info

I acquired a domain about a month ago. It's a .org.uk TLD and I was going to use it to start a small PBN. I've never built my own PBN before however I've researched a lot about them and many people recommend using fake WHOIS info. I did that with this particular domain and also got domain privacy. However I recently received an email from my registrar that says they received a complaint about inaccurate WHOIS information. It says I have to send verification within a couple of days to confirm that my info is correct.

My question is, how could someone complain about inaccurate information if that info is protected with domain privacy? Also, how do you guys provide false info and keep from getting caught?