No, what it does is it does provide a link to your entry, but if they aren't on your flist they can't actually read it. However, now that they have your lj address, they can check out your public posts and friend you etc...plus it does show the subject line of the post and the first five lines of the comment. Which means, you have to hope the commenter didn't put anything revealing in those first five lines. There is a "fix-it" going around that removes the ticky boxes but if the commenter has their LJ set to automatically crosspost than the fix-it doesn't work.