Last night I watched a news story which mentioned a Zettabyte.  I know these terms can be confusing, and even I wasn't sure of the size of a Zettabyte.  So let's start small and work our way up with some easy to remember comparisons.  Every step up is 1000x bigger than the previous step.

A byte can be thought of (typically) as a single character.  This is the "base" unit for comparison.

1000 bytes is a kilobyte.  That's roughly the length of a joke or very short story.

1000 kilobytes is a megabyte.  You can think of that as a small novel, or if you're old enough to remember, about the capacity of a 3.5" floppy disk.

1000 megabytes is a gigabyte.  That's the size of a movie from Netflix.

1000 gigabytes is a terabyte.  That's a thousand movies!  Ten terabytes could hold the entire U.S. Library of Congress.

1000 terabytes is a petabyte.  That could hold over 13 years of HD video.  50 of these would hold the entire written works of mankind from the beginning of recorded history, in all languages!

1000 petabytes is an exabyte.  It's hard to imagine that much information, but it's believed that 5 of these could hold all the words ever spoken by human beings.

1000 exabytes is one Zettabyte.  According to the story I watched last night, this is how much surveillance data the NSA supposedly collected last year.

Seriously?  I knew they gathered a lot of information, but that is stunning!  Also, the congressional committee for intelligence said this was not an invasion of privacy, since nobody knew they were being surveilled, and thus did not complain.

I notice some sources say the NSA data centers can hold one Yottabyte.  That's 1000 zettabytes, and about the size of the entire internet.  Over a high speed connection, it would take about 11 trillion years to download that much information.  

Quoted Text

...the congressional committee for intelligence said this was not an invasion of privacy, since nobody knew they were being surveilled, and thus did not complain.

So if the rest of the law follows that logic, it's okay to set up hidden cameras in bathrooms and change rooms, and as long as a "peeping Tom" isn't caught by their victim, the victim's privacy hasn't been invaded, so no crime has been committed?

I agree danmick, it's crazy.  But true.  http://www.zerohedge.com/contr.....-your-privacy-violat

Quoted Text

You can’t have your privacy violated if you don’t know your privacy is violated
- Mike Rogers, Chair of the House Intelligence Committee