Oh really? Did you look it up?
I tried to debug this to find out where this comes from and checked out the sources for the seam-security-external package but wasn't able to find it - which does have a great chance that I just didn't find it because I don't really oversee the complete code.
Maybe I should have another look at this then.
(I will also try and ask for this on the seam forum but I have the impression that the external part of the seam security is not actively maintained because the main developer has a different focus these days.)