Hand gestures can be an effective tool for communication — but they also can carry some negative associations. In an effort to spread a little online positivity, the Vancouver-based art blog Booooooom put out a call to readers for "Friendly Gang Signs," Instagram pictures that reappropriate gangland hand gestures to produce affirming, heart-warming messages. Readers responded enthusiastically, and the first round of Instagrams went up yesterday. They often take a little work to decode, but they're usually worth it. Take a look at the gallery above to see some of our favourites — and if you have trouble interpreting them, there's an answer key at the end.