You think you have MIL woes? Oh, to have your problems!
My MIL is insane.
Literally.
She send mail to us with the names "Judas" for DH and either "Bi***" or "Ho" or "Gold-digger" for me. (Where's my gold!?!?! I feel gypped lol) She sends things from my husband's childhood (like photographs) with her insane ramblings written on it in red marker about how he betrayed his parents by moving to Alabama to be with me and stuff.
She's written on envelopes that she wishes our house would burn down with everyone in it. She's never seen her grandchildren. She didn't even know about our two boys til this year. The only time she has ever been to our city is when she came down here to try and get me in trouble with the police. They saw her for what she is though, totally nuts.
She's said things in the past to my DH like "I wish I could slit your throat and watch you bleed all over the carpet." I'm not making this up! I've never even met her in person because she hates me with a vengance.
I almost feel sorry for her. There's no way she isn't insane. God help her.
ETA: Almost forgot, she also sent photocopied, anonymous letters to my entire neighborhood saying awful things about me. Some neighbors showed me the letter, it was her distinctive handwriting.