Capturing with Wireshark for a certain web site


Hi, I have installed a WireShark software. I assume that you already well know what it does, this software. I studied a several youtubes videos. But still need to know much much more.

I tested to start capturing on my PC, went to google and typed ‘test’ then pressed stop capturing in non-promiscuous mode. Then found something like ‘http’, selected something like http/1.1 /verify the found under Hypertext Transfer Protocol, ‘test’.

What I need is to capture or intercept all the text for a certain website, worldwide, not just on my PC, but all PC’s or MAC’s or whatever went over the network for a certain period of time, any text being sent over a certain http:// address, I would be able save to a text file. For example, like gmail account or ftp account or anywhere the password and user name is required. Sounds like this is a hacking.
Is this possible?

Some instruction, would be a help.

Surgey, regards.

Waiting for replay…