$500 for a ransom, sound like kids playing around in the park... Script kiddies at work. The FBI will give them rope to hang themselves...
They will allow this to happen, to trace their origin... and the NSA will gather the data.
The Tor network on exit nodes will reveal their identity and they will get busted soon... mark my words.
It's one thing, when you target soft targets like schools... it's another thing, when you target law enforcement agencies. This will be seen as a terrorist attack, and be dealt with extreme penalties.
This is also bad publicity for the whole Bitcoin community, and should be frowned on.