Listwashing is the process through which individual entries in mailing lists are removed. These mailing lists typically contain email addresses or phone numbers of those that have not voluntarily subscribed. An entry is removed from the list after a complaint is received.
Only complainers are removed via this process. It is widely believed that only a small fraction of those inconvenienced with unsolicited email end up sending a proper complaint. Because most of those that have not voluntarily subscribed stay on the list, and only the complainers stop complaining because they are removed, this helps spammers to maintain a "complaint-free" list of spammable email addresses. Internet service providers who forward complaints to the spamming party are often seen as assisting the spammer in list washing, or, in short, helping spammers.
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