Taken back? Finding a person is one thing - you need a lot of resources to track a person down - then trying to find where they may have hidden the keys needed to use the Bitcoin is another. People who have stolen millions of real dollars are still able to just hide the cash or money in off-shore accounts. Similar problems exist, though it doesn't start off anonymously. It's not really good or bad, it just is. We need to manage for best case scenario, and structure systems to provide best case scenarios. Controlled or rather fully-manageable ecosystems are the best, though they have the ability to be badly managed and through political lobbying, etc. cause a whole series of problems in a society.