> Should they be keeping track of all newly-passed (and rescinded) laws, as well?
Largely, no, because it would be a spectacular waste of their time. Why? Because the regulations are usually microscopically focused on class of actors that (a) know they exist, and (b) have a vested interest in staying current.
Moxie Marlinspike's example of the undersized lobster rule is especially telling in how it goes against the very point he was attempting to make. On the enforcement side, this particular regulation likely affects fewer than 10,000 people in the entire country -- that is, people fishing commercially for lobsters. The public interest it serves is that fisheries are subject to the tragedy of the commons[1], and must be regulated to preserve these public goods. It's basically the equivalent of that little tag on your mattress that says "ILLEGAL TO RESELL" -- people joke about getting arrested for this. No, it's targeted at the vanishingly small number of people that sell mattresses commercially.
EDIT: Also, just a note -- laws are passed by Congress. Regulations are promulgated by agencies that have been delegated some task or authority from Congress ("we don't have time to draft/debate/vote on every little piece of trivia regarding airplane part advisories or what plants are on the invasive species list or what next year's technical specifications for automobile safety are -- FAA, USDA, NTSB, you guys have the experts and scientists, so here's your authority, now go and figure out the details and make it happen")
I understood the point he was making to be that under a strict interpretation of the law/regulation in question, there is no flexibility around whether you have it because you're intentionally harvesting undersize stock, or whether it was thrown at you from a passing car as you walk home. If the act of possession is illegal, then the rest of the circumstances are irrelevant.
Of course, any reasonable court would/should dismiss this, even in the unlikely instance that someone would decide to prosecute, but the problem is that is a dangerous thing to rely on. And if it were recorded by not prosecuted, it's now a liability that can be used against you for other reasons, until the statute of limitations applies.
If the law prohibited selling, or possession in a commercial context (large lobstering boat, etc), it would be reasonable. The damage to lobster stocks is likely[1] due to the large commercial concerns, rather than individuals catching small numbers for personal consumption.
Likewise for the 'it's targeted at the vanishingly small number [...]'. If the law isn't specifically targeted at them, why not? One good reason would be the creation of loopholes that allow it to be broken without penalty, but if the alternative is allowing perfectly normal activities to bear the possibility of prosecution, subject to the whims of the legal system, I think I'd be in favour of being precise.
Largely, no, because it would be a spectacular waste of their time. Why? Because the regulations are usually microscopically focused on class of actors that (a) know they exist, and (b) have a vested interest in staying current.
Moxie Marlinspike's example of the undersized lobster rule is especially telling in how it goes against the very point he was attempting to make. On the enforcement side, this particular regulation likely affects fewer than 10,000 people in the entire country -- that is, people fishing commercially for lobsters. The public interest it serves is that fisheries are subject to the tragedy of the commons[1], and must be regulated to preserve these public goods. It's basically the equivalent of that little tag on your mattress that says "ILLEGAL TO RESELL" -- people joke about getting arrested for this. No, it's targeted at the vanishingly small number of people that sell mattresses commercially.
[1] http://en.wikipedia.org/wiki/Tragedy_of_the_commons
EDIT: Also, just a note -- laws are passed by Congress. Regulations are promulgated by agencies that have been delegated some task or authority from Congress ("we don't have time to draft/debate/vote on every little piece of trivia regarding airplane part advisories or what plants are on the invasive species list or what next year's technical specifications for automobile safety are -- FAA, USDA, NTSB, you guys have the experts and scientists, so here's your authority, now go and figure out the details and make it happen")