Max I wonder if it would be helpful for Mudcatters to scour the DT for songs that may be published by HFA clients. If indeed they continue to harass and threaten litigation, we would then know exactly what offensive material would need to be expunged. I can volunteer my services for that or any other concerted Mudcat effort to lighten your load in this fiasco. From another perspective, despite the claims of "A Publisher", I've found in my dealings with publishers and rights clearinghouses that although they claim to act as a proxy for composers and lyricists, their interests are not always in line with their clients. For instance, copyright term that extends well beyond the life of the composer benefits these agencies far more than it does the estates. As laborious as it may sound, seeking the permission of like-minded artists represented in the database may at least up the ante in your favor. The express permission of at least the regular Mudcatters represented in the database could be a good start. Barry Finn has the right idea here and his letter might be a good place to start a new thread.
Anyhoo, are you indeed seeking contributions to offset legal fees and whatnot? If so, I'd like to fedd the kitty.