Unique wifi networks in DB: 134,416,539
Unique networks w/ location: 132,748,862
Unique wifi locations in DB: 2,147,483,647
Networks with WPA2: 51,884,201 (38.5%)
Networks with WPA: 14,531,452 (10.8%)
Networks with WEP: 24,478,931 (18.2%)
Networks without crypto: 89,527,723 (66.6%)
Networks crypto unknown: 20,301,486 (15.1%)
Networks with default SSID: 4,543,738 (3.3%)
You're right, 66% of all networks found in Wigle is pretty limited.