I think the policy of deleting any song they claim (and can prove) copyright to is the correct one. This will show to any court that you are acting in good faith by complying with their more reasonable requests. The only problem is for them in that they have to trawl through the tradition files which can be VERY time consuming. If this bunch of pimmelkopfen are really after Mudcat coughing up quickly, then they may just give up. Bob