The difference is that the connections on G+ hold much less meaning than the connections on Facebook. Facebook automatically populates specifically-named friend

The difference is that the connections on G+ hold much less meaning than the connections on Facebook. Facebook automatically populates specifically-named friend lists based on your network data and asks that you refine their lists to improve their data collection. Essentially, users who choose not to provide Facebook with their close friends, family, university, and location will be scoped out and tagged by their own friends using these smart lists. It's a disturbing strategy for data collection.