I know people use packetsniffers like Wireshark to determine what traffic that is unwanted to filter out and blahblah CISCO blah.
Unwanted traffic? Filter out? No. No, no, no. A packet sniffer captures packets. It's just a troubleshooting tool. If you're wanting to, say, build up your firewall rules, doing it with a packet sniffer isn't the best idea; try a port scanner (this is another tool which I use on a semiregular basis).
Also, I'm disinclined to listen to you when you say things like "and blahblah CISCO blah". Try to be precise when you're discussing technical concepts, please.
But there are programs out there that can sniff in places they're not supposed to.
No, actually, there aren't. You can't just say "i wanna sniff the traffic all the way over there today!". Did you perhaps confuse reality with a bad television show? Or are you talking about how one can sniff traffic on shared-medium networks (cf wifi)? Because that's not strictly illegal either.
NB: You might also be thinking of a rootkit, but your phrasing suggests a certain amount of handwaving. Can you perhaps elaborate on
this remark a little further? Your vagueness isn't really helping me get a handle on what the everloving fuck you're thinking.
Simply enough, I mean that if you're unauthorized to go sniffing around, then by law (and I mean derp law) that's illegal.
This is what you just said: breaking the law is against the law. Thanks for that elucidating insight!
And I also know what a packet sniffer does =.= Just it was late. And I was derp
I'm pretty sure that you don't, tbqh. But you are being pretty derp. Have fun with that.