I am not sure what Roll20 is trying to do when I start it up and log in to one of my games now, but every time I have started to get a warning from my antivirus that it blocked a website due to Trojan. I close out the warning and the game loads just fine, so I don't know what the warning is actually about...but it seems to have started this only recently, coinciding with the advent of the Jumpgate feature.