@Jelaweb: yup, you're right, miscalculated that one.
@Magrus: OK, I removed it.
but, when I say it's common knowledge, I mean you can get that piece of information with the Gather information; DC being 5 (I'm sure WizardsOTCoast would appreciate the pun)
it's basic math.
you start with 0XP
to get to 2nd level you need to gain 1000XP
to get to 3rd, you need to get additional 2000XP
now, try to guess how much additional XP you need, to gain 4th level (it's 3000)
also, if you say that reveling information from PHB is illegal, that means that every site on which there is/was a discussion on usefulness of a prestige class/feats/or whatever should be closed down, because they have revealed supersecret info that "Weapon specialization" adds +2 to damage to a selected weapon.
it would be illegal to hold a copy of PHB for everyone to download from your server, but I'm pretty sure that it not illegal to share information that's located in it (it might sound stupid, but the Universal Declaration of Human Rights; Article 19 states:
Everyone has the right to freedom of opinion and expression; this right includes freedom to hold opinions without interference and to seek, receive and impart information and ideas through any media and regardless of frontiers.)
so, there. unless USA became communist country over the night, you have nothing to fear.