That's because they cannot tell you how to operate your business. There were no laws dictating how to log.

Well - As Bill Clinton said, what's your definition of Anonymity?
Here is how I define it:

an·o·nym·i·ty ( P ) Pronunciation Key (n-nm-t)
n. pl. an·o·nym·i·ties
The quality or state of being unknown or unacknowledged.
One that is unknown or unacknowledged.

anonymity

n : the state of being anonymous

But you could get very reasonable amount of anonymity taking certain precautions couldn't you? Say like using a new wifi card in a lappy on a liveboot cd and a free hotspot? Would that create damn near perfect anonmity? Long as you avoided going to the same spot all the time and using a different nic to log on @ home or anywhere else.
Yep, you can take steps to do so such as these but they do not guarantee that you won't be snagged. There are proven techniques to catch sneaky bitches who do just what you have described. Sorry, can't tell ya.