I never thought anyone would outdo Nobis Tech/Ubiquity but someone has...
http://www.spamhaus.org/sbl/listings/velocity-servers.net
What effect does a ROKSO listing have? Once listed on ROKSO, all IP addresses determined to be used by or under the control of the listed entity are preemptively listed in the Spamhaus Block List (SBL), regardless of whether spam is emanating from them or not. All domains determined to be under the control of the listed entity are preemptively listed in the Domain Block List (DBL).
Timeouts for ROKSO SBL records become indefinate (the ROKSO listing overides any expiry/timeout of the SBL record). SBL records belonging to ROKSO spammers appear in Yellow "(ALERT)" tags in SBL listings pages and are prioritised for urgent attention by ISPs.
A listing on ROKSO means that the spammer or spam gang's activites are brought to the attention of Cybercrimes units of Law Enforcement Agencies Spamhaus works with in the spammer's country. Many Law Enforcement Agencies have specially-arranged access to 'classified' non-public ROKSO records and use ROKSO data to help track down and bring to justice spammers violating any number of laws when spamming.
Many Internet networks use ROKSO to vet prospective customers or check if suspicious customers are listed before granting connectivity and IP space. ROKSO is an invaluable tool for Abuse Desks and legal departments of ISPs looking for information linking spams reported to the spammers behind them.
In addition many Internet networks nowadays include clauses in their Acceptable Use Policies/Terms Of Service which specify that being listed on ROKSO is grounds for termination of the customer's account (specific clauses visible here).
Hosting 3 ROKSO operators when there are only 100-150 ROKSO operators in the entire world...quite an accomplishment.
How many ROKSO spam operations are there? For several years the number of known professional spam operations in the ROKSO List has been in the range of 100 to 150 outfits.