In-laws or out-laws?

WARNING: very negative and whiny post here!!!
I know everyone, or a lot of people can complain about their in-laws. But, I think mine might actually be in the running for the worst set in the United States. Here's a quick overview: My MIL is an alcoholic to the point she is hurting herself because she is always drunk. She knows she's killing herself and she doesnt care and refuses treatment. My FIL also an alcoholic but is more functional than MIL, but he also does a variety of illegal drugs, plays in a band and still thinks they are going to "make it someday". He is also atheist, verbally abusive to his wife and sons, and is so closed minded that even if you prove that he is wrong, he will still argue that he is right. they come down to visit about 2 times a month or more and they drink as they are driving the 2 hours trip down. And that's just some basic background on these people. How their sons turned out decent is quite amazing. I am uncomfortable with these people around my children for so many reasons. One being all the drinking. They are always drunk. Always. When they were still allowed to babysit, my daughter was about 4 months and son about 18 months. I had worked a busy nightshift and they were babysitting while I was sleeping. I woke up at 11:30 the the sound of my daughter crying like she was in pain. I waited, and waited for them to comfort her. Finally I got up and found both MIL and FIL feeding my son who was perfectly able to feed himself at that time and my daughter downstairs, alone, in the swing shrieking. She was in her PJ's as well as the same diaper I had put her in when I put her to bed the night before. I knew it was the same diaper because I had used the last Huggies diaper. (We always used pampers b/c they don't leak, and we had problems with breastmilk poop running out the back of huggies). Her diaper was so saturated, the diaper stuffing had turned to gel and was all over her. Needless to say I took her upstairs, changed and bathed her, breastfed her and she was fine. My in-laws response? "I guess she just wanted to nurse again". I won't get into the conversation that followed, but they were no longer allowed to babysit unless my br0 and sis in law were around.
They were down this past weekend. Luckily I had to work and my hubby wasn't working. But they managed to make a mess of my house, stuffed my children full of chips, cookies and the sort instead of decent meals and drank an enormous amount of alcohol. I'm talking 2 JUGS of wine for my MIL, and about 2 cases for my FIL. And I had to break up a fight between the two grandparents b/c FIL was yelling and cursing at his wife in front of my kids. It was a fight over how much charcoal she thought we had of all things. Hubby and I are considering not allowing his parents down unless they can control their drinking because I worry about the safety of my kids, and frankly, they are poor influences. Not only the drinking, but their lack of spiritual beliefs. Not sure it's going to go over well. Hubbys brother and sis-in-law are also considering doing the same once they get pregnant. Having a plan to do this is the easy part. Actually doing it is the hard part. Anyway, I feel better getting that off of my chest. I apologize again for such a negative post.