Some people are able to live their lives and try to solve the conflicts by dialogue, by speaking with others; only in extreme cases, they look for a lawyer in order to get help, when things can't be solved by dialogue.
Other people, by some weird reasons, escape reality and forget about dialogue. So, from their distant ivory tower, they think that reality has to fit their wishes, or else a lawsuit is required to change reality. For them, dialogue means nothing, and their preferred way of solving any conflict is sending a lawyer letter requiring, on supposed legal grounds, to change the behaviour of other people.
This would qualify as a good definition of "severe lawyeritis", a disease affecting some famous & rich people who think their money is enough to scare anybody and force them to follow the supreme wishes of the guy affected with the lawyeritis.
But reality is not like this. And reality does not care about what disease you have, or what kind of ivory tower do you live in.
So, when a particular musician sends lawyers letters even to close members of the band of his glory years, you can say that something is going deeply wrong with that guy. First you send lawyer letters to real copyright breakers, then you send lawyer letters to people who did not sign a confidentiality agreement, then you send lawyer letters to administrators of fansites (who are basically supporters and lovers of your music), then you send lawyer letters to former close friends...
I wonder where is the end: maybe to send lawyer letters to yourself, to say "wake up, guy, you are losing your mind"??