From an Account on up to 10 Associated Devices,
Provided no more than 5 are iTunes-authorized computers.

from Apple (Ft. Hella Apple Lawyers) – ITunes Terms of Service 3 on Rap Genius

Although, as stated above, you are the only one who has the authority to use your iTunes account, we will pretend that your entire family does not use one single account, and will pretend that you own some combination of iProducts numbering a maximum of 10.

We wish you would buy 100 iProducts, but then it would be too obvious that you are not the only one using your iTunes account, and that this whole thing is a sham.

To help improve the meaning of these lyrics, visit "ITunes Terms of Service" by Apple (Ft. Hella Apple Lawyers) 3 and leave a comment on the lyrics box