Best Buy's cellphone upgrade checking utility. If you punch in your Sprint mobile number and ZIP code, you get taken to a screen showing all the other numbers on your account as well. This applies only when yours is the main number on the account, mind you, but the issue is in the obviously lax approach to securing data you might care to keep private -- Verizon, AT&T and T-Mobile customers have to pass a security check first. Of course, the actual risks resulting from someone being able to find other numbers associated with your cellular account are so small as to verge on the benign ("somebody can use that... for something", as the KXAN report sagely advises), though that hardly excuses Best Buy from being sloppy with Sprint subscribers. They're human too, you know!