After the first one I would have thought: "Hey, I lost a major project, and a backup could have prevent that." - After the second one it's more like "How can I be so stupid to lose another one??" - but three??

enter password? doesn't your company have an HR? how can it even be possible that someone else has access to your computer! If you can't speak up for yourself, ask for IT to block all those Sites on your PC!

Get his ass in the grass

You're upset about projects? I'd be pretty disgusted that my boss was masturbating in my chair! What's he using for Spooge Capture?

That stick figure **** will do it every time.

What kind of IT team do you have? Don't you guys have firewalls, user account logins, even the most basic anti virus? If nothing turn on the windows defender. It took 3 lost projects to find this out? YDI.

I would be more worried about him trying to blame things on you.

depends on state and what op do having a password on work computer can lend to fines and maybe jail

Just back up what you need, wipe your computer, and report him.

If you've got proof, go to HR, get his ass fired.