Facebook "PLEASE DO ME A FAVOR" request is rubbish, a good explanation why...
nakedsecurity.sophos.com
nakedsecurity.sophos.com
I don't use Facebook. But other people in my home use Facebook which means they're tracking what I do—as a non-user and someone that hasn't agreed to their terms or privacy policy—anyway. The only solution to this is for Facebook to stop tracking people when they log out. The government needs to step in because they obviously won't do that on their own.
There are some pretty reasonable objections to Facebook revealing things unexpectedly: this isn't one of them. If you wish to control who reads a message you've left on a someone else's quasi-public wall then Facebook certainly isn't the service for you.
While I understand what you're trying to say and agree with that, I think that the issue people have is that Facebook is giving them a mechanism to exert that control and then that mechanism doesn't work.
> Custom means that the post will be safe to comment on with no leakage to strangers via the ticker/news feed.
No it doesn't. It means you don't know the privacy of the post, and it may be more or less limited than the 'Friends' setting.
The best advice from the article:
> And don't forget - next time you leave a comment on someone else's Facebook post, don't say something that you may later regret.
Never do this on HN either. Same concept.