[All clients] Privacy issues of linking pictures and videos from third party sources
It is dangerous to run untrusted javascript in the chat window and view pictures and videos from untrusted server (I hope I don't have to explain it more), therefore instead of one option - "show pictures and videos in the chat window" there should be two options - first for showing only pictures and videos received from other peer (sent through p2p network), and second for showing pictures and videos from the Internet.