Is it possible that watching a load of youtube videos could affect my bandwidth cap?

I Don't really know a lot about this but recently i had to go without my television for a couple of weeks whilst it went in for repair and for my TV needs i constantly watched programs on youtube from TV channels and such.

My question is this; How much usage is one youtube video? Let's say a 5 minute youtube video for example because i have been watching so many over the past couple of weeks and i really don't want to go over the limit which is about 30gb and end up getting fined by my ISP.

Also can your ISP see what websites and what youtube videos you watch? I don't really like the fact they can see everything i do... not that i have anything to hide, would a program like Peerblock stop them from doing that?

There is a cap? I didn't know. I have the cheapest internet from AT&T for $25 a month and I used to watch alot of stuff from Youtube and they never gave me any problems. They never mentioned any cap that I know of. Is this cap just a European thing?

Thanks for the info. I never knew. I must have gotten lucky so far, but I will be much more careful now with my downloads. I don't have Netflix, but I assume it probably uses alot more bandwidth than even Youtube. They really should print this info in the monthly statements.

Some ISPs offer a choice of overage fees or speed reduction. You should definitely check with your ISP to see whether they offer this. That way the only consequence for running over accidentally is that your speed sucks until the end of the billing month; with some ISPs going over doesn't always cause the intended speed decrease, and if that's the case with yours so much the better. :)

I'd also recommend logging into YouTube with a YouTube or Google account and changing the profile settings to say you have a poor connection. This will make videos default to 320p, which is good enough for most purposes; without this change the video will jump up to 480p if you go into fullscreen mode or make the windowed mode larger, and when this happens the download size is noticeably increased.

Using a video-capturing browser addon such as Flashgot (for Firefox) will put an icon in the status bar that you can hover over to see the total size of the YouTube video you're watching (YouTube's buffering bar shows how much of that has been downloaded). This will also work for some other video sites (e.g. Blip.tv); those that deliver video through dynamic streaming won't show an icon so you have no idea how much they are using.