I bought this WiFi Adapter for my laptop, based on "Very good" to "Excellent" reviews found on the internet. BTW, not to be confused with a household router. This antenna picks up WiFi broadcasted signals from nearby routers [Including those from neighbors]. Prior to the hookup of the unit, my laptop's internal wireless WiFi picked up 4 other signals from my neighborhood; of which one was "Unsecured" [their WiFi connection not password protected].
After installing the software and using only the basic small 'rubber ducky' antenna, I receive ELEVEN signals from other sources [signal strength of 10 measured above "Good", while 1 measured as "Fair"]. Out of those 11 other WiFi connections displayed, THREE were unsecured! And this was using only the small 5dB antenna. I can only imagine what I could receive using the extended magnetic roof antenna in my car, near an apartment complex!
One of the three unsecured signals came from a neighbor who named their connection as "@home 4482". Obviously, their house was easy to locate [since they included their address as their network name]. They were a little shocked when I knocked on their door and suggested that they password protect the WiFi connection.
And, 'No'; it is not illegal to view a display showing other WiFi networks. It IS illegal to access them. Nevertheless, a simple password isn't going to stop anyone with the drive [maybe someone like me!] of hacking into your connection anyway. Just for giggles, I may simply follow the directions given on one of many YouTube videos on how to do that.
At any rate, this unit is really efficient. I bought this unit from Buy.com [now called "Rakuten.com"] because they INCLUDED the magnetic 9dB roof antenna accessory at no extra charge. Alfa AWUS036H 1000mW 1W 802.11b/g USB Wireless WiFi Network Adapter With Original Alfa 9dBi Rubber A - AWUS036H + 9dBi mag base $43.00 including shipping from Buy.com.