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I have just started my very first corporate job at a big company this week, and they issued me a personal laptop (not shared with anyone else). I've been told that they monitor the internet fairly strictly (not a problem in general for me - when I'm at work I'm working), and I'm worried about my login information to big websites (primarily Google) being compromised. It might be paranoid, but when I look at the HTTP headers on my side, I always see my username and password sent in plain text.
So far it hasn't been a major issue - I accidentally logged in to Gmail the first day, but then I changed my password. When I get a cell phone that has better reception in the building (my phone has abysmal reception), I'm going to 1.) tether my personal laptop to it so that I can be secure entering my username and password without IT having access to it and 2.) turn on the Google two-step authentication on a per-login basis. Until then, though, should I be really worried about IT being able to have access to my login information? Will using HTTPS help? Do I really need to be this paranoid about this?
Addendum: I Just realized, I also would prefer it if they didn't even know my login name to certain sites, like Wikipedia, stuff that I just don't think it's any of their business to keep track of, but which I'd prefer to be logged in to for various reasons (the whole SE network, for example - I'd love to be able to vote and I use various SE sites at work all the time, but I don't want them seeing what questions I've asked or what I've answered - that's just not information they need to know). Does HTTPS protect this information somehow, or is this something I just have to give up if I want peace of mind?