I don't friends-lock most posts, and I would really appreciate it if people didn't cross-post comments etc. from the ones that I do lock, since this apparently means that the security of friend-locked posts is compomised. If anyone does so and I find out about it, I will de-friend them.
But even before the new stupidity, there was no way to stop one of my "friends" putting the contents of one of my friends locked posts on line if they wanted to - it's called cut and paste, and there isn't a way to stop it. And that is just as true of every other social networking site.
The bottom line is, I won't be quitting livejournal over this, but I really would appreciate it if people would think carefully before cross-posting.