Spend a moment to think about why, and why this is not an issue for Google and for Facebook.
If all of the text, all of the pictures and all of the logic are packaged as a HTML5 app, then once anyone gets a copy on their disk, then they can just pass it to their friend, with no revenue for David. If David puts in a simple call home at startup then a) the app is not usable offline and b) it is still easy for crackers to work around.
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