Can a site tell if I screenshot it?

no, a screenshot is basically a picture of your screen.

OK, I am going out a limb here with the extreme scenario. The question wondering if it possible for someone to know is not always going to be a big no, but it would be so extremely difficult to implement security measures of that level it might as well just be impossible.

How could it be possible? Active Scripting that goes unchecked or malware from said site and at last, an Operating System with some nasty software on it (unusual but possible) to where the concept is to monitor "keypress" codes sent from the keyboard (of which this is common in other applications) and integrate the results in a web interface or a 3rd party DLL allowing transmission of the results back to the originator.

Basically, I'd say it is approx 99.99999% safe, for now...

If that site has a script running that logs keystrokes (PrintScreen, Alt + PrintScreen), perhaps. But not common... Unless the site is a bit shady kind. But if you actually have a keylogger running on your side, you have much more serious things to worry about than the site owner figuring out you taking screenshots... he can figure out much much more. :P

If you're using Windows 7 and use Snipping Tool, no chance. Usually. ;)

They can track you while your on there site if they want but most likely they want. If you just do a screenshot in logical sense no they would have to be at your home or spying on you. lol

nope they wont know at all.

Its basicly taking a screenshot of a site with ur ipod. If u do so, of course they wont find out!

:)

haha, never will they find out, no matter how much technology advances, even in the next 100 years or so, they will still never find out.

No.

simple no.