Should I be blocking my laptop's camera?

I don't see any opportunity to blackmail me. There's nothing to imagine, my 'pornface money shot' wouldn't look any different than my National Geographic face. I doubt anybody in my contact list would be surprised to learn I watch porn, if they know me at all.. As for the $10000, once I stopped laughing, I'd invite them to come pick up the money. Target practice can be a good thing.

how did you know?

You just know that kind of thing ... .

Sometimes you do just know. It is possible to be wrong, but such knowledge is right far more often than it is wrong.

I had such a creepy feeling that I never had before or since.

The LED comes on (maybe).
You hear laughing coming out of your speakers.
You see some camera-related tasks pop up in task manager (and system slows down maybe).
Or, sometimes, you just know.

Lots of good thoughts on cameras but how do you turn your mic on and off?

I know, as big as a pain and inconvenience, the best way to disconnect camera and mic is to shut the computer down, shut it off and unplug. Waiting for it to boot up only takes a short couple of minutes. Problem solved.

... protect me while working on it.

Also, the "few short minutes" can easily last n-times the time for one of those quick-quick queries I often do. And that's only if Win10 doesn't pick that moment to start a major upgrade - they do seem to try and sneak those in whenever you reboot ...

It is possible to boot a computer remotely and it is possible to use it to spy even when it is off. However, if your laptop is actually closed then the camera is covered. The microphone is harder, but it is still possible to do something to disable or muffle it. Microphones are generally located inside the closed clamshell, not on the outside. If you look on your owner's materials, they will tell you where it is. A little piece of cotton would help. It just needs to be thin enough that it will not interfere with the closing of the laptop. The better it insulates, the better it muffles sound.

I used to have headphones that had a mic and there were two separate cables to plug in. Nowadays, there seems to be only one headphone jack and nothing on the front of the computer to plug in a mic (maybe on the back). But I used to unplug the microphone cable. I live alone so all anyone would here would be "Cat, quit shredding the rug!". Sometimes I do screw up by being on the phone in front of the computer. I need to watch that.

First, on a Windows laptop, just go into Device Manager, and disable (drivers for) camera, and microphone. Done.

As for the Police, or the NSA, or ?????? monitoring you, it's been done, at their discretion, for many, many years. What, you thought FISA warrants, and such were something new? I've read that the microphone of your old Bell Telephone landline remains active even when you "hang-up". i expect the mic on my smartphone has same problem.
Oh, and for the record: "I LOVE Big Brother!"

We do not know how the hardware in laptops is set up. We know how it is supposed to operate, but that does not mean that there are no secret "features" or settings that we know nothing about. It is fact that people have been spied on without knowing it.

I wound up unplugging my microphone from my desktop computer because Cortana was always interrupting my private conversations wanting to know what we said. That might sound humorous, but anything we talked about, even if it had nothing to do with me, showed up in the ads the next time I got on my computer. If I mentioned that my godson liked racy anime (he does) I would be inundated with ads for anime products and for videos that showed such content. I would also get some sexually suggestive ads that assumed I was male. If I mentioned that my plumbing needed to be fixed I would get ads for plumbers and plumbing supplies. These things have nothing to do with what I do online or what I search for. Now as long as it is simply innocent conversation that is simply creepy. However, we do also sometimes need to have private conversations. For whatever reason, we need to know that we are not being listened to. At such times I do not allow cell phones, computers, or smart devices to be in the room.

This happens to us ALL the time, too. Last night I mentioned a friend's son was going to a midwest college (I'm on the East Coast) and immediately, everyone in the house started getting sidebar ads for that university, as well as other products with the same word in the name.

Those who claim that this is "coincidence" are really burying their heads in the sand. It happens to nearly everyone. Some things just can't be coincidence.

Come on, I have no problem about covering the camera or the mic, but if your friends think the government has magic tricks to use your whole screen as a camera, maybe they can explain why the same government couldn't even 'hack' into an iPhone a few months ago. The next question is why the CIA is so interested in what you do. Only you know if you participate in anything illegal.
On the subject of the microphone, I have a hard enough time getting the people I'm talking to listen, and I know there's nothing worthwhile in my conversations.
My final point is, if the laptop is powered off it can't take pictures or record voices. Without power, neither will work. There's no magic involved.

Powering off is not so easy as it seems. If you think "shut down" powers everything off, you haven't had the stress I've had with various technology re-starting, updating while I thought it was off, and what not. If you're not worried at all about this, you might need to learn about identity theft and consider whether you trust random hackers or others who might use your image and audio in ways you never dreamed of.

For some reason, it seems the same person is stalking me in this thread. I should have mentioned I have been in the business of Information Technology and specifically data security for over 30 years. Fortunately, retirement from this conversation is coming faster than my real life retirement. There are settings to allow your laptop to 'wake up' to do updates, or be remotely controlled, or NOT. Working in the Financial sector means I don't "need to learn" about identity theft. I'm not going to get into what I ever "dreamed of" here.

Actually, if you go back and investigate, they were able to get into that iPhone.

It has happened. It has happened to people who were no more "interesting" than you are. Don't assume that it will never happen to you. Don't be paranoid, just be intelligent enough to pay attention. Don't do anything that you don't want others to see with a camera in the room. Don't talk about anything private with microphones of any kind in the room.

Do you ever sit in front of your computer wearing....? Am I wearing clothing right now? You can't tell because I have an external camera located in my desk drawer. There is a whole rule book for people who do video conferencing (meetings, interviews, etc.) that many people don't think of, like locking your cat out of the room, to what is on the wall behind you, to your posture, etc. But we are not talking about active cameras and mics during a video conference here. There have been a lot of hacks of people getting control of these devices when you think they are not active. Even if you think others are being paranoid, it doesn't hurt to take very simple precautions. And how often do you check your "light". That is, if it turns on at all during an issue. It really is up to you, though. It is what YOU feel comfortable with. Wait, I have to go put some clothes on...