I created this animation in After Effects using the puppet tool. I started with a stationary straight line animation I made in Photoshop (to get the hand drawn look), then deformed it with the puppet tool. Wash, rinse, repeat.
I created this animation for my math class to illustrate the equation c=(n^2 - n)/2, which gives you the number of connections between a given number of nodes in a fully connected network. For example, in the last sequence, there are 7 points. (7^2 - 7)/2 = 21, so there are 21 lines/connections in that arrangement.