intellectual property

Not-so-hypothetical situation which is thankfully not my own:

A significant other gives you a computer. You use it, you write on it. You break up.
A year later or so he becomes enraged, lets himself into your parent's home, and takes the computer.
The police tell you that the files aren't yours, and never were.
He, according to them, has all rights to the writing, can post it, publish it, whatever. You don't really care about the computer.

I think this is a huge intellectual property issue. I recognize that when you type or work on school computers or for classes that the school essentially owns your work (especially if you sign a contract saying so, as I've had to repeatedly). I get this distinct idea that the law enforcement officials might be mistaken here, but then again, the significant other very carefully researched the law before he did this as well.

So who owns the writing?

And what does that *say* about electronic writing?