Because I couldn't find a tight net...

Looks like EA changed there mind over some features that should have been in Spore from the off. From The Consumerist...

"EA's DRM spyware on the long-awaited game Spore turns out to have an added side-effect: if you live in a household with multiple players, you all have to share the same account. The game's manual says otherwise..."

The manual does indeed state that...

"You may have multiple Spore accounts for each installation of the game." page 52

However after a rather large thread on Spore official forums, "EA_Violet" kindly states that the manual was, well...

"That section in the manual was a misprint and will be corrected in future printings of the manual. There is one Spore registration/account per game/serial code so you are correct in that you cannot make multiple accounts at this time."

With the recent confirmation that similar DRM is going to be in C&C, it looks to me that EA on their quest be all "New" and stuff, is also assuming worse than ever, that we are all dirty rotten pirates...

Update
Jim presented this a bit better here...