{
"type": "pin_removed",
"user": "U024BE7LH",
"channel_id": "C02ELGNBH",
"item": {
…
},
"has_pins": false,
"event_ts": "1360782804.083113"
}
When an item is un-pinned from a channel, the pin_removed event is sent to all members of that channel.
The has_pins property indicates that there are other pinned items in that channel.