Tagging copyrighted text

[Marc.Ringuette@GS80.SP.CS.CMU.EDU]

Tim May and many of us argue that copyrights will become unenforceable 
as copying bits becomes cheaper and crypto privacy and anonymity becomes
more widely available.  This will mean that any static collection of
bits will just be FREE.  Musicians will have to make money on live
performances, because they couldn't sell many recordings.  Etc.

A question I've been thinking about is, will Dow Jones be able to charge
for its newswire?  

Step 1:  I subscribe to Dow Jones and then relay each message to a
mailing list, charging them a fraction of the original price.

Step 2:  Dow Jones starts changing random whitespace in the text, in an
attempt to "tag" the text untraceably to trace which subscriber is
leaking the information.  They cancel my subscription.

Step 3:  I get 20 new subscriptions, and use the redundancy to cancel
out Dow Jones's sneaky tagging.

Step 4: ...


Question:  who wins?  I haven't been able to work it out yet, but
it may just be a simple combinatorial exercise.


-- Marc Ringuette (mnr@cs.cmu.edu)