cable box

is it illegal to purchase a cable descrambler box if it is used for other purposes other than viewing cable tv, for example covert security cameras? i am being sued by a local cable company- they state that i purchased the unit for illegal viewing of cable tv, however that is not the case. i had been a p.i. for ten years, covert security cameras- home ond buiseness cameras wre one of my specialties(employee theft, nanny cams etc.) i used many different items smoke detectors, radios, etc. and of couse the dreaded cable box!
how can i be charged with stealing cable????? how do i defend myself?

Where?????