Defining piracy to be theft takes the meaning out of the word "theft".

I believe copyrights that restrict individuals are an unjustified burden on society, and so I would never support the copyright industry by paying for copyrighted content.

I generally prefer to use free software (even using pirated software contributes to its ecosystem) but if I must use non-free software, I will not pay for it anyway. Given that I would never pay for it -- whether I use it or not, using the word theft is silly: A resource isn't being moved from one place to another. A new resource is being created, in the privacy of my own environment.