Probably. I have seen many colleagues across the cubicle aisles spending their time on things completely unrelated to their work. I would be baffled to hear that you have not had similar experiences.
Well I've done the same too. But I would not use my work PC.
Absolutely. Yet as a hiring manager, I see it all the time.
As a hiring manager, do you hold that behavior against candidates for positions where poor security practices could become a major liability for your company?
I don't even use my home PC for interviews, but instead use a refurbed laptop with a clean OS install.
Blame the lowest guy on the totem pole and not his garbage leadership with a terrible approach to securing the company's vaults. Wow. This industry eats its own or throws them under the bus -- anything but criticize its terrible leaders. What a shitshow.