bazza - try getting your facts right
TSG (The SCO Group) litigation was about contracts, not copyrights. According to TSG, when IBM added code to AIX that made the functionality the property of TSG. Linux destroyed the value of Project Monterey, a joint venture by companies (including IBM and TSG) to create a single Unix for multiple architectures. TSG claimed that IBM broke a contract with TSG when it increased the value of Linux by adding TSG's functionality (that was designed by IBM, and implemented by different IBM programmers for AIX and Linux) to Linux.
TSG said they owned the copyrights for Unix. They actually had a contract to collect royalties for Novell's Unix, pay all the money to Novell and in return Novell would pay TSG commission. TSG's litigation with Novell was about the lack of transfer of copyrights, TSG keeping Novell's Unix royalties and TSG suing IBM over Unix without authorisation from Novell.
TSG also sued former customers because the licence agreement required customers to count the number of installations of SCO Unix they used (zero) and post the results to TSG every year. When the letters stopped arriving, TSG sued ex-customers for breach of contract.
TSG made a lot of noise about copyrights they did not own and patents they did not have. They pressured some companies into signing a contract to pay royalties to TSG for any TSG code or patented material that might be in Linux. The contract was the source of revenue, not STREAMS (Licensed GPL and contributed to Linux by SCO, ignored by everybody and deleted from Linux when TSG started threatening every penguin on the planet).
I am churlish enough to say that BlackBerry have come out from under a other people's bridges and are trollishly demanding money to cross. There is some strange belief that this behaviour is acceptable if the company doing it does (or used to) manufacture something.
Patents were supposed to increase the rate of technological progress by rewarding inventors for publishing the details of their invention so others could use them. Software patents at best describe functionality that is obvious to those skilled in the art. The time consuming part of adding functionality is creating code that implements the functionality and the test vectors that ensure the functionality survives debugging, optimising, porting and feature creep. Software patents (== computer implemented inventions) do not include code (which is protected by copyright), so they do not increase the rate of technological progress because they do not include details that allow others to use them without doing all the work of coding and testing.
Judges are beginning to understand this, and have set precedents reducing the value of patent portfolios. Some states recognise the damage that patents do to their SMEs, and have passed laws to place barriers in front of trolls. Filing in East Texas is by itself evidence that BlackBerry knows it is trolling, and would lose on appeal if their victim has the cash to last long enough. The reason BlackBerry has not been snapped up is they believe their patent portfolio has greater value than experienced trolls are prepared to offer.