Re: all webcams I know have a light on them to indicate if they are active..
I quite often use my laptop in the bath. It rests on the side and I can type into it fine, although I wouldn't want to do any serious writing or coding like that. If it fell into the bath (it never has because I position it so it can't) it'll probably be knackered, but it's all backed up and I'll get a new one from my employer.
I'm pretty confident this will never happen though.
I also join conference calls from the bath, and the bog for that matter. Handy thing, the mute button. Nobody ever knows.....
As for the webcam, there's a light which comes on, and even if someone could see me, they're not going to see anything exciting. Just my face watching the screen. Potentially a little screwed up if I'm squeezing one out.