But it is nearly impossible to tell from a newspaper account of the ruling.
Clearly, if someone decrypts a wifi broadcast, or otherwise deliberately frustrates the owner's attempt to secure the connection, that's dodgy as hell and should be prosecuted. But the judge rather pointedly says sniffing an open connection can also constitute an act of wiretapping.
And here is another instance where a lawyer is using his faulty knowledge of science and engineering to craft policy, rules, and regulations. Pretty sure that the Supreme Court and FCC have already ruled that receiving Over-The-Air broadcasts are legal, absent any other use by the receiver. Used to be that any bar or pub had their own OTA antennae and TVs without any additional payment to the local stations, but when caught snagging the early unencrypted cable signals got fined pretty heavily in addition to having to pay back the cable companies.