From what I recall, modern graphics hardware has little or no support for video overlays. The fastest and easiest way to display video on modern systems is actually to feed it through the standard 3d-accelerated compositing stack, which means that it shows up in screenshots just like everything else. Some content providers don't like this because it provides a way to capture the video, so they insist on graphics hardware manufacturers providing some method of displaying video that blocks screen capture; if any modern graphics cards do support overlays it's almost entirely for DRM purposes rather than acceleration.
The original MS blog article that somebody linked seems to say "no plugins", though. No Flash and no Silverlight is just a corollary of that. If they allow extensions, how would they prevent Flash?
A reminder that MTGOX originally stood for "Magic The Gathering Online eXchange". When a site designed for trading cards online turns into the world's biggest Bitcoin exchange you better believe there's not going to be an appropriate level of security underneath it.
It doesn't really seem like a dig at the MtG subculture, IMO. It's just natural that a trading card site probably would focus less on security than a financial institution. This has nothing to do with the people or the hobby involved, and more to do with the fact that pretty much nothing needs as much attention to safety as a bank/currency storage.
As an ex-developer of a company who had servers co-located with them, I'm feeling mighty smug about using our own backup system instead of their in-house one.
As mentioned earlier, bandwidth in Australia is prohibitively expensive so the choice wasn't as simple as "use both".
Depends on your tolerance and method of usage, but I use it 2-3 times a week, using a vaporiser, and go through ~0.1 grams a session. Due to taxes where I live (Victoria, Australia) it's cheaper than alcohol.
If it's anything like SNES/Genesis/other console emulators, the only entropy source is player input. I can't imagine many arcade machines would have a true persistant clock, and even then you could just store the start time as part of the replay data to ensure you get the same output for rand(time()) each time.