[rights-requirements] General permissions expressions in XrML

[Aaron Burstein <burstein@boalthall.berkeley.edu>]

Here are some thoughts on an issue that we discussed in the last two 
calls.

1. We have been asked by the SC to answer the question: "What do we need 
that we cannot express today in the syntax" of XrML?

2. Example:
         a. A purchases a sound recording from B.
         b. A wants to excerpt parts of the sound recording for use in a 
published review of the recording.
This example requires that A be able to (1) take the excerpt, (2) 
incorporate it into his review document, and (3) publish the review. 
A's readers then require permission to listen to the excerpt.

3. Conversations in the SC, in related contexts, have suggested that 
XrML can express the permissions that A's use requires AS FOLLOWS
  a. A may obtain these rights either by direct grant from B, the rule 
maker; or,
  b. A may "self-issue" a set of rules that permit the relevant 
exercises; or,
  c. A may obtain the permissions he requires from a trusted third 
party, such as the United States government.

These options may be theoretically available, but assuming they
are, using XrML in this way is practically and politically  impossible.
The reasons for this are as follows:

  d.      (Regarding 4(a).) One way to characterize A's predicament is 
that of a market failure.  Relying on B's willingness to grant 
permissions to cure a market failure, when B is the cause of that 
market failure, is absurd.
  e.      (Regarding 4(b).) A's ability to express the required 
permissions is separate from A's ability to exercise those permissions.  
A cannot exercise the permissions that A issues to himself unless A is 
trusted by B to issue these permissions.  In effect, this alternative 
reduces to the preceding one.
  f.      (Regarding 4(c).) Once again, this alternative requires the 
 trust of B, the rule maker and it requires, in this particular 
instance, the government to craft REL rule sets about particular 
copyrighted works arguably in particular contexts. Sending A to any 
third party for permissions imposes burdens of cost, delay, and loss of 
privacy on A.  The notion that the Government could or would express 
REL's granting the relevant permissions in this context is absurd.  
Involving the Government in this way is both politically and 
practically untenable.

4. Thus this question and example highlight the distinction between what 
is theoretically expressible and what is practically expressible.  We 
find XrML wanting in its practical ability to support rights associated 
with the use and exploration of copyrighted works.

5. To the extent XrML is offered as an all purpose rights expression 
language itmust provide practical not purely theoretical support for 
the expression of rights in domains it intends to support. If XrML's 
authorization algorithm allowed expressions of context to enter the 
authorization decision, this kind of problem could likely be solved, or 
at least alleviated. If context is ignored in authorization 
evaluations, however, a class of rights (expressed as permissions), 
similar to the case described above, is practically impossible to 
express.

Aaron Burstein
Dean Rowan