The New Google Zebra Update coming soon to battle the abundance of spam content on the web. Panda hit on-site elements. Penguin mainly focused on off-site issues. Zebra is going to town on social...
1. Too many retweets with keywords included around a link
2. Face book updates with too many shares from people not in your industry
3. Any Google+ shares as this will look spammy (Google+ is a graveyard right, so any activity looks suspicious?!)
4. owning a Pinterest page - brands only use these for SEO benefit no?
If you've been creating great content which may be being shared extensively by people on the web, some of which might not be bloggers in your niche, then start looking over your shoulder.