Why and when did OpenStreetMap introduce 'Add Friends' feature?

General talk
1

Currently, I am doing a research on ‘Investigating and Improving the involvement of Digital Volunteers in OpenStreetMap movement’. I am curious to know why and when did OpenStreetMap introduce ‘Add Friends’ feature in OSM.

2

Look at this:
https://github.com/openstreetmap/openstreetmap-website/commit/7d52305640d647d97c7904e447ad48e6d0e2f694#diff-34d0d6625292151d9b2b1d188a6c3b0f

So it was in 2007 probably. Pretty much at the beginnings of OSM as we know it, I guess.