I'll first start out by saying congrats to the Stacked team for an awesome new release of ES 1.3.26.

Before posting this I very carefully thought out different scenarios to ensure accuracy of the pinned system.
Proposal/Gist: Display pinned post at the top on one's own profile/group/event but not on others. Promoting an old post is fine on your own profile, but not on everyone's.
The Problem: On a user's own profile, the implementation of pinned post's seem to be working perfectly. Unfortunately it displays on other people's profiles as well.

You can see this here:
I thought pinned posts was intended for promoting one's posts on their own wall, group, or event? By having it on other profiles it is basically taking over other people's activity stream. In the best case scenario having it display on their friend's profiles will make it more difficult to find the stream items related to that person. On a much darker note, the current design is a huge vulnerability to abuse. This includes spam, bad intentions, or people who overly self promote. Saying something in the stream is generally okay (even if it is bad, it will only affect those friends who viewed it from the stream), but having it display on all of their friend's profile feed (especially many posts) is asking for trouble. Furthermore it currently displays on everyone's feed instead of just friends. So take the
Stacked user for example, he has no friends yet still gets all the sticky posts on his profile.