Governments could legislate1 a 'buy back'. Corporations could seize assets via heavy handed legal action. ISPs or agencies could subjugate the network via technical (ISP/Backbone) level filtering, man-in-the-middle attacks, denial of service.
What could be done to the bitcoin network to prevent - say a government, corporation - from network/developer/miner coercion? How resilient would Bitcoin be to any of these 'social engineering' scenarios?
At the technical level, consider ISP port filtering (ala Bitorrent) (I have not read the whitepaper as to how much thought was given to this). Bitcoin Network Monitor, Bitcoin address <=> IP monitor, ISP subpoena, etc. If BTC nodes end up requiring services similar to TOR to survive, what chance does legitimate BTC usage have?
Offline, deposit only 'cold' wallets could protect against technical efforts. Pre-existing software security solutions might help when applied to BTC (i.e. randomize Bitcoin port, bundle Bitcoin-QT with TOR, one click cold wallets...)
Hoarding physical cash might prevent 'bank' level manipulation from effecting you, similar to cold bitcoin wallets. Think of physical fiat as a cold wallet, and electronic fiat as online wallets.
The benefits of 'running your own bank' might not seem significant if you can't connect to the network (i.e. you can't process transactions).
/TheEndIsNighRant
1 1933 Emergency Banking Act
Quote
authorize the Secretary of the Treasury to order any individual or organization in the United States to deliver any gold that they possess or have custody of to the Treasury in return for "any other form of coin or currency coined or issued under the laws of the United States - http://tucnak.fsv.cuni.cz/~calda/Documents/1930s/EmergBank_1933.html