Here is a page on which atheist parents and teenagers are talking about how to treat children. The discussion began with someone complaining about teenage girls, and includes comments from people who think that more discipline is called for, but a couple of posters mention TCS, and a couple of others seem to advocate a more TCS approach.
UPDATE: Elliot thinks the above should have been worded much more strongly, like this:
The discussion began with someone looking for endorsement in hurting his daughter, and includes comments from people who think the daughter should actually be hurt more.
and has asked for more warning in such cases next time.