A blacklist is not directly interfering with your business. They just provide a list that contains IPs, your IP, and say we have seen spam traffic from it in the last x hours. The mail receiver, who trusts and uses the list might be interfering, but it is his right to pick and choose who he is accepting email from. Same right you have to pick and choose who you let into your bar, apartment, club, house, ... what so ever.
Safe your 500 bucks per hour. A lawyer will not do anything
But I do know the "enemy" of my "enemy" is not necessarily my "friend".
I've seen the nightmare of the next Internet. Whether it's micropayments for digital stamps, or slowly refilling quotas, or hard hierarchical controls, it's more power to central authority.
I know I'll never win this argument.
The Internet will keep fracturing and normal citizens will get more frustrated. There will be a change. But just like the hatred of social media, lurking underneath it is an insatiable thirst for power.