New to Bitcoin? Start here! <-- please add known issues to it

[mindsplit]

Please add some of these to this sticky (or make another sticky):
https://en.bitcoin.it/wiki/Weaknesses
https://en.bitcoin.it/wiki/Common_Vulnerabilities_and_Exposures

Maybe some smart people will notice and start working on it.
We should make bounties for unsolved problems in the bitcoin protocol. I would pay 0.1 if someone has a resolution for the current malleability bug.