ICANN Report on Whois Data Reports System. Over 18 months, complaints on inaccurate Whois data for 16,000 domain names were received by ICANN and forwarded to the registrars (the complaint form for inaccurate whois data is here). Registrars may cancel a domain name registration if it contains misleadingly false whois data. It is unclear how many of those names actually had inaccurate data and of those, how many were corrected or deleted as a result of a complaint (regostrars were not required to report back to ICANN how they resolved complaints, although there was voluntary compliance with regard to 65% of the complaints). The report contains extracts of user complaints and registrar responses and makes for interesting reading.
Something to think about: at least 20% of the complained-of names apparently had something to do with spam. Given the prevalence of spoofing and other DNS abuses, what should/can ICANN and domain name registrars do about spam (if anything)?