As per Marc Kupper:
When someone is not logged in there's no link to the preferences. I logged in, learned the URL is http://www.isfdb.org/cgi-bin/mypreferences.cgi, logged out, and went to that URL. Everything was checked under "Web Sites" except the first four items. As a test, I changed the preferences to only show the first four sites and saved them. I then pulled up the same publication record from a different computer and now it's only showing links for AbeBooks.com, alibris, Amazon US, and Amazon UK.
It looks like there's a bug where the preferences for not-logged-in users can be saved and then apply to everyone using ISFDB who is not logged in. I also was able to change the language selection. That one shows the SQL and I learned it's updating the settings for user ID 0.
I've restored the standard defaults for user 0.
Anonymous
Fixed in:
biblio/submitmylanguages.py 1.4
biblio/submitmywebsites.py 1.2
biblio/submitpreferences.py 1.6
biblio/mywebsites.py 1.2
biblio/mypreferences.py 1.7
biblio/mylanguages.py 1.6
Installed in r2013-123 on 2013-10-05.
Closing.