bug tracker spam

[Glenn Morris]

On bug tracker spam:

1. I think Stefan's suggestion to reassign spam to a "spam" package
(as documented in admin/notes/bugtracker) is better than closing the
bugs. With the latter they get archived with all the rest, with the
former they are more easily separated from real reports.

2. I think somebody (or bodies) does a very good job of moderating
bug-gnu-emacs, so that I almost never see spam there (thank you!).

Yet the bug tracker collects a fair bit of spam that has to be dealt
with separately. Where is this coming from? Is there no way to combine
the moderation step with removing the spam from the tracker, to avoid
duplication of effort?