Why Should You Not Use ns1.vshosting.cz And ns2.vshosting.cz As Recursive Nameservers

Servers ns1.vshosting.cz and  ns2.vshosting.cz are authoritative nameservers.

Authoritative nameservers should never be used as a recursive nameserver. The reason is that authoritative servers could keep records for domains that are not delegated to it yet.