No, and we don't want to!
Like any Internet transfer, our sites have to know the IP addresses that contact them; without that, no communication is possible. But we do not trace, hold or examine them beyond what is necessary to deal with any problems or maintain logs or statistics. We never identify IP addresses with people.
Further, we encourage people, sites, schools around the world to mirror, or copy, our texts to their sites. Once that happens, we have no control over them, and we never have any idea who or even how many people access them after that.
Even further, we encourage people to distribute the texts on disks, CDs, paper, and any other storage format they can find. We encourage them to convert the texts to other formats, and share them.
For most people reading this, anonymity is probably not an issue, but you may live in a place or time where reading Paine, or Voltaire, or the Bible, or the Koran, is considered suspicious or even subversive. We don't know who you are, and what we don't know, we can't tell.
Currently (2004), by means of DRM (Digital Rights/Restrictions Management) many commercial publishers can make a list of exactly who is reading which of their eBooks. We don't know, and we don't want to know.