Esprit d'escalier time. My stepfather Ian, an accomplished and successful playwright, was politely listening to my rant about the iniquities of software patents. I didn't explain it very well then, but here's what I should have said (and probably will, assuming his patience doesn't run out):
Let's say you've just written a play for Radio 4 called Love with some unusual features - it's about an elderly couple, one of whom is an Anglican priest who has been deeply in love with the other, newly widowed, for the past 47 years.
Assume the play is (as indeed it was) rather successful, and Radio 4 commission another three episodes to continue the story. Now the twist: a letter arrives from an American attorney, stating that her client, who has never written a play in his life, has nevertheless done some valuable research into narrative science and has been granted a patent on the idea of any play which involves a relationship between two characters, one recently widowed, the other a cleric of any religion, where the cleric has been in love with the widow for at least half his lifetime previously.
Obviously the attorney must protect his client's intellectual property - she cannot permit highly visible figures such as the author or the BBC to commit intellectual property theft in broad daylight - and for a mere 50% of the royalties and a joint writing credit they will very reasonably permit the production of the remaining episodes.
Can't happen in drama, so far. Can happen, is happening, in software. And it's only going to get worse.