I made a mistake with serious ramifications when I edited RSS.pm. Who knew a > could cause so much trouble?
< open(OUT,">$file") || croak "Cannot open file $file for write: $!";
> open(OUT,">:utf8",">$file") || croak "Cannot open file $file for write: $!";

The above code added a > to the beginning of each filename, generating RSS feeds with names like %3ecrimson_news.rss. When I first saw queries from these files, I assumed that someone's RSS reader was broken (I should have looked at the HTTP status code. Sorry). The problem is fixed now, though.