Scientist Dallas Weaver has suggested that if copyright holders want "property" rights then they should be subject to a significant fixed annual tax in order to continue to hold the copyright. This tax would encourage copyright holders to put their works in the public domain.
Read more about it at "Copyright This."
Someone should have talked to an accountant (or even a book author) before tossing up this idea. Apart from the distinction that already exists between tangible (e.g., real property) and intangible assets (something that it is very difficult to assess a value on), what about depreciation allowances and how is income for the IP to be handled (since it can be non-exclusive and not diminish the asset)?
Basically, a stupid idea.