suddenly i need an internet connection and an unencrypted SSID appears. here is what i do with that specific SSID:

  1. seek for an SSID named "Speedy". if exists, connect to it with a random RFC1918 ip address space with /24 subnet mask
  2. open Wireshark, look for an IGMP packet
  3. select that IGMP packet, take note of the source address. if the configuration is default, "" is appeared. else, you're out of luck unless you can guess the subnet mask
  4. change your wifi interface connecting to that SSID with a random ip address inside address space. take the bottom part, e.g. 235
  5. open and put 'admin' as username and password when asked. if it is not accepted, you're out of luck.
  6. seek for wireless configuration, and you can see the real SSID and passphrase
  7. enjoy free internet :v

YMMV. goodluck.