Edit: reflecting on my comment I realize everyone, me included, is looking at this wrong. There is a Constitutional issue - Fourth Amendment "secure in papers and effects". Nobody has a right to just look at & act on the contents of your "papers" (now extending to digital video etc), and contractual access thereto must be respected. You may not like the contracts limiting access to something, but you have a natural obligation to respect them. Copyright and patent law were stopgap measures in place for where such controlled access was hard to implement.
Just a thought.
There is also a physical difference, which has been pointed out many times: if I take your car and dinner plates, you no longer have them. If I make a copy of your data, you still have it.
There is also a contemporary debate about whether the term of ownership for physical property should be for limited times, or whether rent should be charged on physical property. Of course, the debate is not framed this way, it is instead framed in terms of levying property taxes, sales, taxes, and inheritance taxes. This is another example of how framing the debate can affect the outcome.