I'd propose an (incompatible) change to the whois server:
do not send "changed:" records unless a special option is given.
Neither on inetnum, route or person objects. As every changed: record
contains an email address clueless people/programs go for that. We often
receive complaints to addresses that are listed in changed: records of
persons that are admin-c or tech-c for abused hosts (and some records
date back to 1996 and are no longer under our control anyway).
An e-mail has just been sent to the db-wg mailing list from Engin Gunduz
discussing the use of the "changed:" attribute. Perhaps this would be a
good moment for you to send your comments, subscription details can be
found at: