Can my cellphone be traced if I used a library wifi to send a message on a school site using their contact us portal? I sent a message basically but I am wondering if they will see that it came like from an android or apple phone will show on their end? Will they able to trace it via the source info?
They can "track" it the same way as they would any other computer.
I haven't seen too many libraries with paranoid security teams, but they can figure out quite a bit if they are setup for it. For example unless you took some precautions, they can infer:
- what browser was used (and infer the device make/model from it)
- that it was used from the library WiFi
- what date/time it was used and ( if necessary ) cross link it to the physical building-entry records (if the library building has access control)
- if you library WiFi uses any form of network access control or even store MAC addresses in their logs, then they can tell it was your cell phone
Further, if a crime was committed during that time (no, I don't mean this about your message) and if law enforcement is involved, they can also:
- narrow down to all the people who were physically present in that approximate area (e.g., Library building) using cell phone tower VLR records & tower-triangulation
- if they investigate your phone, the can tell that you had accessed the portal at that time and maybe (yes, maybe) even that you were the one who posted that message. Of course, this might be irrelevant to the matter they might've been investigating - but technically, they can.
Just for laughs: If you had to login as yourself to either your library WiFi access control or the school site itself to post that message, well... :D