The CONTENT you might be listening to via HD Radio can (if the content holder so chooses to distribute it in other ways) be heard via several methods…including internet/streaming (webcasting) or internet/download (peer-to-peer file sharing like the old Napster), or traditional AM & FM radio, or even satellite radio (Sirius and XM).

Based on that you said you were listening at work, I’m going to guess you’re listening to a webcast on your computer. There is no direct cost to you for doing this, not unless the content provider charges you initially (and you’d know it; you would’ve had to have provided a credit card number). However, your webcast IS taking up a certain amount of bandwidth on the company’s internet connection which could, depending on the company, be a violation of company rules.

So yes, you could get fired depending on what your company’s policy is on listening/watching webcasts. Although I’d have to think your job performance would have to be pretty marginal before you’d get fired for something as “small” as listening to a webcast at work.