Whenever we add a new friend, this activity gets pushed to the newsfeed of a random subset of our friends.
This seemingly happens even if our friends list is set to private.
Is there a way to keep our own friending activity private, and it to be pushed out to our friends?
I found also this discussion on facebook: How do I stop my recent friend activity from appearing on my friends' newsfeed? , and it seems that these guys found no solution as for now.
same thing happened to me. this helps though:
http://www.readactor.com/articles/how-to-hide-all-friending-activity-on-facebook/
On the Facebook wall,on the right hand of your recent activity you’ll find a button from where you get two options, to remove the post (nothing new) and “hide all friending activity” A popup window needs your confirmation. Also there you have a link to your profile story settings manager. You can access at any time this settings.
Same thing and with the “like” notifier. You can now hide all “like” activity. Actually, you have now a more flexibility in set the privacy options for almost all things what are posted on your Facebook wall. Test this settings yourself!
The profile story settings manager unfortunately is not easy to be find. You can spend time to take a look in any profile or account setting but you never find it. The link for this settings is placed at very bottom of your Facebook wall. Scroll down your wall, wait to load stories, scroll again and there you will find the link pointed in the previous screenshot.
Go to your activity log. At the top it will say posts and apps, switch to all. Now you will literally be able to see everything you did, including the things you searched for on Facebook and the profiles you viewed. You will also find friending activity you hid, so you can unhide.
Best Answer
The other answer linked in the comments says you can remove the stories and the stories themselves match the privacy of the activity
For example, as far as I know if you don't want a 'X is now friends with Y' (where you are 'X') story appearing to your other friends, set the visibility of your friends list such that they can't see it, then they'll only see that 'X is friends with Y' story if they're also friends with Y and can see you on their friends list.
TL;DR - if i can't see your friends list, i can't see stories about who you became friends with unless i can see THEIR friends list and see you on it