jeez - where to start.
probably best to do some Google researching!
no, a normal person cannot see a list of users and their activity.
they can't even see a list of connected devices unless they log onto your modem/router - which is why it is important to always change the default username/password they come with!!!
and once logged in, they can't see the data being transmitted and received within the menu system of the modem/router.
you need packet sniffers and all that black magic crap - not impossible but not everyday knowledge either.
then there is encryption to get past - even if they get the data out of the packets, they still have to crack the encryption - again - not impossible but well out of reach of the normal person.
and NO! - never share your wifi password with external people. visitors/friends to the house, sure. but you have no idea what the neighbours will do or who they in turn will then give the password to. before you know it, everyone with wireless range is hanging off your modem.
and, it gives them potential access to your network - printers, shared folders, other connected devices etc.
and public wifi hotspots are a breeding ground for all manners of idiots.
they are open systems, usually without passwords, often run by retailers with no idea of network setup so leave default settings as is making hacking a very easy process.
I certainly don't log on to them and if you have to, definitely don't do financial transactions or enter your password to access your emails or stuff like that.
