Update:
DH asked to be allowed to monitor the accounts as well and was denyed by BM. This is when she told them not to sign on at our house (so we couldnt hack).
DH called MySpace yesterday and was told that without a court order they could do nothing. If BM approved it and is watching it, it is allowed. They said they would delete the account if he insisted, but there is nothing in place to stop it from happening again. DH's concern here was that then he would have no idea what was going on because he might not be able to find the new accounts.
DH is going to approach from a few different angles now:
He is thinking of creating his own account and sending a "friend request" and see if it is honored. Then he at least can see the pages even if he cant control them. We have a feeling the "friend request" will be denied though.
Another thing he is thinking of is to find out how to get a court order or something to allow him access to the account without her permission. He was thinking of calling the district attorney's office to get information. Not sure how this will pan out either.
As for internet safety, we always enforce and explain to the kids. They know what is expected of them at our house and what is acceptable. However, when they are with BM they are allowed to do anything, sometimes it seems even encouraged to do things that are not allowed at our house.
We can tell the kids what we expect of them all day, we can tell them we are disapointed or even punish them for breaking the rules. But if BM is encouraging this behavior, why wouldnt they do it?
BTW Davy, 9 and 12 year olds are a little too old to "train", they are not dogs. They do have free will, and if that free will is encouraged by an authority figure...