Boy, I'm not sure lack of SSL is the reason you shouldn't do this!
check your contract. Undoubtedly they have a clause stating you must use your work device for the companies interest only.
I did have an administrative employee recently that spent all her time on Facebook, and didn't produce any useful output at all, and clearly had to be let go - we tried to work with her to improve, but she just didn't care.
Under the employment laws of the country where we operate, it is very hard to fire somebody. Performance related dismissals take forever, and are very expensive in terms of administrative, legal and opportunity costs. Larger companies can probably afford that, but small companies like ours cannot. Our choices are simple: Either spend a lot of time, money and effort in trying to get the person fired on the basis of insufficient performance, where the outcome isn't certain, and where we likely have to end up paying a few more months salary even if we are successful, or pull her up for provably excessive use of company computers during work time for private purposes, and fire her on the spot.
Does that make us jerks? I don't think so.
It goes beyond personal use. Odds are you signed an agreement that says "Anything I do using company resources is owned by the company."* So you have to be careful for any open source work, startup ideas, etc that you may have. Don't do it at work or on your work machine (even at home). * If your agreement says "everything you do is ours," it's already too late for you. I never sign those contracts.
You could use a raspberry pi at home for example
Funny, for a second I couldn't tell if this was about Glassdoor itself or the people who browse it from work.