Macrovision objected to the devices, which remove its copy protection from both VCR and DVD signals, making it simple for a user to copy movies (though only in analog format). Earlier this year, the Court agreed and issued a preliminary injunction against Sima, which was upheld in June.
Several other companies and organizations are siding with Sima, however, and are heading back to court. Macrovision's ACP is fairly easy to get around and found to be more than an annoyance than anything. Personally, I hope Sima gets their way. Too often people are trying to tell you what you're allowed to do with things you own. I think the quote from EFF sums up the entire situation quite nicely:
As the EFF puts it, "If Macrovision wins, digital video innovators will be stuck carrying the albatross of Macrovision's analog noise for years to come."
Let's hope this turns out for the good.