Hi Thomas!
I found out through feeds.scripting.com that I have one other subscriber who subscribes to my RSS feed (who is a member of feeds.scripting.com anyway). Hi Thomas :) (The logs show that there may be others.. but feeds.scripting.com lets me put a name to my subscribers.. I wonder if that's something people will mind).
Presumably you wouldn't share your opml with feeds.scripting.com if you didn't mind people knowing what you subscribe to (here's my list). But I imagine a lot of people will have some things they don't want people knowing they subscribe to.. Perhaps this is a feature that aggregators would benefit from - “public” and “private” subscriptions.. public ones being written to the default opml and private ones somewhere else.