Max Keiser is correct.
Governments would find it difficult to impossible to confiscate (or outlaw) bitcoins effectively. The reason is for every action governments might take bitcoins can be routed around. A government outlawing bitcoins would simply drive their use underground.
Regarding confiscation Max Keiser references Roosevelt confiscating gold in 1933:
http://en.wikipedia.org/wiki/Executive_Order_6102...he issued Presidential Proclamation 2039 that forbade the hoarding 'of gold or silver coin or bullion or currency,' under penalty of $10,000 and/or up to five to ten years imprisonment.
...Executive Order 6102 required all persons to deliver on or before May 1, 1933, all but a small amount of gold coin, gold bullion, and gold certificates owned by them to the Federal Reserve
There are several differences bitcoins would have from the above. First, gold or silver being tangible items could be argued to be natural resources. Governments often feel automatic authority/jurisdiction over such things. This along with the argument "hoarding of gold" was prolonging the depression probably seemed sufficient basis to push the action through.
For people not wanting to comply what were their options? The threat of men with guns showing up with metal detectors, and rewards for nosy neighbors was probably sufficient deterrent to try hiding large quantities of the physical stuff.
On the other hand bitcoins are obviously not natural resources nor tangible at all. One could literally hide/keep secret over 1 trillion dollars worth of value from the government in the form of a bitcoin
brain wallet, which of course is immune to metal detectors, satellite imagery, nosy neighbors or whatever other means governments might successfully employ to locate physical things.