It's really funny that people are afraid of bitcoin becoming obsolete due to quantum computing, but forget how their money is stored.

How do you think your online passwords are protected on servers? How does a bank know that it's the employee logging in, not a hacker? How is military communication encrypted? How do they control satellites?

If a quantum computer learns to break sha256, you'll have more things to worry about than bitcoin. Also, quantum computers are not owned by normal people. These are multi billion dollar installations run by groups of scientists. Even if they finally defeat the level of encryption that will allow them to take possession of a bitcoin address, doesn't mean they'll start stealing money from people. Most people want to do good, aim for the Nobel Prize, not to end up in jail for theft. When they publish they research and show it's possible, we'll have time to update the protocol.