Are you referring to Wi-Fi nic cards provided by universities to their students to access their network for "free"?
Are you suggesting that there is a special Wi-Fi Network interface card that if I had I would be able to access all the other hotspots I mentioned without paying? Please point in the direction of one of these "magic" nic cards.
Most of the places I use Wi-Fi to access the facilities internet connection identifies my computer (or nic card) by Mac Address. If this address is not on their pre-approved list, you "see" their network, but can not access it.