Board Thread:General Discussion/@comment-35301431-20140702193241/@comment-53539-20150207185546

Modifying the software is still illegal.

But yeah, XSYing vocaloids brings into a lot of copyright questions, especially if the two studios behind the vocaloids have slightly different rules. IA and Miku, for example, follow different guidelines just on character and voice. This is going to be a grey area regardless for a while. Since its "new" XSY is going to be a controversial issue for a while.

Considering how ad the results are, right now, XSY isn't such a great thing and I've yet to see what the fuss is all about.