I saw a great video by Molenyux on some commonly bandied about arguments used by statists:

Hint: one was used by Thugman the other day on the Colbert Report. People always forget that moral catch-22's aren't really possible -- if there are no choices, there can be no ethical or moral context. It's that old truism -- there is no such thing as good if one cannot choose to be evil (and vice versa).

However, real world examples are not quite so simple -- for example, The International Business Times is now bashing Ron Paul for admitting that he collects Social Security monies when there already was no choice in having the money taken from you in the first place. Either way, the Immoral act has already been accomplished. Taking a small amount of your stolen money back or choosing not to take the money back basically has no moral context.

Now it could still be argued that since the government has done more evils in that it has to enslave future generations just to pay these benefits currently, taking the money is bad. However, it must be noted that the bad decision was yet again already made here -- that is the state running this pension program like a ponzi scheme rather than a retirement fund.

So, all that is left is the praexological perspective -- we must consider how this impacts incentives, and whether it encourages you to do good or evil in the future. And from that perspective, taking the 30 pieces of silver is clearly the wrong move here. Deriving benefit from an evil organization like the state will inevitably tempt you to rise in it's defense. This in particular has always seemed to be a blind spot for those like Walter Block who derive benefit from the state, yet rationalize it as helping to "starve the monkeys".