Complex networks are created by social media on the World Wide Web.
They hinge on the spread of information from very small nodes to the whole network when activated. This is what can happen when you tweet.
The studies of how activation happens, what it means to be such an ‘influencer’ and whether similar interactions happen in nature, are rapidly establishing new science and art forms.
Just one recent study is by F Morone & HA Makse, Nature 524, 65-68, August 6 2015.