Originally Posted by Chris
No, but a person acting in this manner could be wide open to a criminal prosecution under the Fraud Act 2006, under section 2 (fraud by false representation, the representation being that they are entitled to sell the TiVo box) - providing they are acting dishonestly, i.e. they knew they were not entitled to sell the box.
The same Act, in section 11, can also be used to prosecute people who buy cable boxes and modems with the intention of getting services without paying for them. The OP seems aware that there's a TiVo charge and, on a certain reading of his posts, also seems to be willing to attempt to circumvent that charge by purchasing a box off eBay (or wherever). Under these circumstances he could be at risk of committing an offence under the Fraud Act. I would say whoever sold the box to him almost certainly has done so.
As I said in post 15, you can make a case for fraud. You won't prove it because as you rightly say the knowledge and intent of the offender are key, and I still prefer to believe that most people are acting honestly and are unaware that they don't own their box-I don't think people commit fraud for the sake of £20 unless it's scalable, and generally people only have one or two boxes to sell. That might be a naive view.