It's a virus that has locked my safari, but has uneffected my firefox which is what I am currently using. It claims to have locked my browser due to illegal activity and claims it requires a payment of 100 dollars to unlock. Obviously a scam, though I can't close safari, go to a different page on safari, or anything like that. Also, it won't let my computer restart because my mac tries to close safari before restarting and it won't let it. I googled it and found that it is a known scam and I seen how to remove it on winows, but I don't know about for a macbook pro. If anyone knows how to do this that would save a trip to the computer store.