If you roll up your back ladder and park where they are unable to "fall" into your boat it reduces the chances of being sunk. You can call your ladder down with a "T" whistle and up with a "Y" whistle. Just a tip to help. They can't grapple up. There are other ways they can still get up and sink, but I don't list them on here to give any turds ideas. I am sorry this happened to you.
In order to properly report, you are going to need names. Screenshots. The more proof you have, the better. I do not approve of this and wish a fix for it comes out soon.