Here's some math. There are 15K harvesters identified by Honeypot. About 20% are US-based. This makes more than 3K harvesters that are US-based and subject to jurisdiction by US courts. With the power of legal process it won't be that hard to unmask the identities of a large portion of these 3K harvesters. With some pressure and threat of damages and expenses of defending a large lawsuit, many harvesters would happily disclose any relationships they have with a spammer - no more John Does - the plaintiffs can now be named. The rest is easy. Slightly more analysis here.