Thank you everyone.
I wasn't sure really if I do have a case to make at this point in time as everything is said to DH or sent to his phone, not directly to me and I don't know if that makes a difference.
I have just been thinking over what I do have as proof.
I took some slightly blurry pictures of DH's phone with yesterdays messages on them.
I forwarded the messages from April 2013 from DH's phone to mine, but that means they came to me via him and don't say they are from MIL or FIL's phone on them. DH didn't keep the messages himself, and has a new phone anyway now.
I have one of the three letters she wrote me which in itself doesn't say anything bad, it's just the fact that she wrote it at all after I had asked her to leave me alone. It is the second letter of the three I opened, I can't find the first or the third letter and I sent the fourth one back unopened. I received that fourth letter on 23rd February 2011 though, I can remember that because it's a family members birthday.
I have an old laptop on which I wrote three replies to her letters and I think those three replies are still stored on it. I hand wrote the short note I sent back with the fourth letter.
I told some on-line friends about these incidents so can probably dig back through my old messages to see if I've got dates or times on any of those things.
And I have the date I called the non-emergency police in 2011 and the 666 reference number they gave me at the time.
But really, the most current things I have are a few forwarded messages from April 2013 in which they threatened to drive around the streets searching for our cars and now a blurry photo of yesterdays messages threatening the same, just turning up at the house.
And I really wasn't sure if that was enough or if the rest was too far back. Or if it will even count as the rest of it's just me saying "they did this and said that and made me feel ill" and MIL very determinedly and miserably saying "I would NEVER do or say any of that, we love her!"
DH knows what they are like. But he's spent all his life as the youngest following the lead of his older brothers and sister, and the rest of their family, in ignoring things for the quiet life.
He does know what they are like, he did speak to them when I first told him I wanted to back off from them and told them how upset I was.
But he's also been brought up all his life watching them do things like this and then thinking that 'sorry' makes everything better. And really it doesn't, sometimes it just can't.
I've posted what they said when we lost our babies before, and it makes me very recognisable because it is so awful.
Basically three days after our baby was stillborn MIL took it upon herself to argue with me about the time he was born, insisting I gave birth an hour or so earlier than I did. She then demanded to know when we were going to try for another baby and finally asked me if it still hurts to give birth if your baby is dead.
I know the time of birth thing doesn't sound like much, but when all your baby has is a name, a time of birth and a date of birth, it matters that people get things right. So even that was hurtful but when she went on to bully me into talking about trying again when all we wanted was our son, it was awful. And then to ask about if it still hurts. She's had four children, she knew exactly what she was asking.
Two days after that she was back, walking into the house without even saying hello, and telling us how terrible her own life was because she was worried about SILs mortgage and had had an argument with BIL. Not one word to us about how we were coping or feeling. Didn't ask once if we were alright.
She also started an argument with DH the night before our son's funeral, because he didn't sound cheerful enough when he spoke to her on the phone and she took offence at the tone of his voice.
From then it went on and on. She used things in the news, like Madeleine McCann disappearing and the debate on reducing the time limit for terminations to ring up and tell me how other people don't deserve children when "people like you" can't carry them, she kept asking if we knew what was wrong with me yet and if they could fix it before we tried again.
When I did get pregnant for the second time she barely took any interest until we also lost that baby. We were in a car accident when I was 20 weeks pregnant and I went into premature labour at 22 weeks and almost died myself from an infection that got to my placenta during an operation to try and put a cervical stitch in place. DD lived for two hours after her birth.
MILs first comment to me when she came to see us (a couple of days after DD's birth as they were living further away at that time) were "We know what's wrong with you. Pre-eclampsia. I know a midwife and I've told her about you, that's what she says did it."
Again there were more and more things after that, for months. Comments about how my babies weren't proper grandchildren like our BIL and SIL's children were, because ours were dead and didn't count. Always referring to BIL and SIL's daughter as her 'first granddaughter' and ignoring our DD. Asking for some of the precious few photo's we had of our daughter and then losing them, finally telling us they turned up in a box of rubbish they were throwing out.
And the final straw, asking if DD had been born with all of her face or bits missing.
She was alive for two hours and was utterly perfect and beautiful, just very tiny. You can see all her face in her photo's too, MIL was just being spiteful for the sake of it that day.
And still I have dreams about being pregnant and being told our baby has died. I was having them anyway, have done since our first DS was stillborn and we were told at the scan that he had died. But since MIL made that comment the dreams always include someone telling me that my baby's face is missing.
That was the moment I knew I was finished with them as far as any sort of relationship went. I was prepared to be civil to them but not to go out of my way to have them in my home or my life. DH was with me when MIL said that, and he told her off at the time, and she took offence because we were being unreasonable to be upset at what she had said when she knew what she meant.
A couple of weeks after this I found out from SIL (married to DH's brother, not SIL DH's sister) that MIL had been lying to her about something I had supposedly said and told DH I was finished, I wasn't prepared to see them alone even for one minute.
DH tries, although I would like him to cut all ties himself. But they are his parents and if he wants to see them I won't stop him. He hardly visits at all these days but he can't seem to make the final break.
I just ask that he respects my decision not to see them and to keep DS away from them as well. Which he does, as far as not trying to force me to see them goes. When they ask him to "make me" see them, and they have phrased it that way before "will you make Alice see us, can you make her speak to us, will you just tell her she has to meet us…" he won't do that.
I know he wishes things could be different, but I know he also understands that they won't be, can never be again.
I don't think he believes they will really come to the house. I believe from past experience of their behaviour that they will if they want to. When MIL gets an idea in her head, FIL helps her to carry it out regardless.
But if they do, I will call the police and ask for something to be put in place to stop them coming again. And I will be expecting him to support me in that because it will be their own doing. Although I know initially we would probably end up arguing about why I called the police, I do think that he would calm down and realise I had no choice.