You mean like broadcast a virus or worm, through an unprotected WLAN?
Yep, someone could do a lot of cyber damage, from public-access wi-fi, and it would be extremely hard to trace it.
yep, or worse, like shut off the power grid. My local electric co-op has an open wifi port a white hat hacker friend of mine uses for free. he said in very short order he could have the town in a blackout if he wanted to. my town is about 20,000 people. No big deal. But try that in a city such as toronto canada, who recently went wifi on their power companies. An open wifi port could cause a lot more damage.