Returning my phone to Verizon... Unlocked bootloader?!

[dezymond]

There is absolutely no way to lock a bootloader, except through ADB. ADB requires a USB connection, and my USB port is dunzo

Yup.

Which is weird because I hear of numerous people unrooting and no USB problems. Even when they re-installed the drivers it got working again.

Good luck though

 

[MarioMaster08]

There is absolutely no way to lock a bootloader, except through ADB. ADB requires a USB connection, and my USB port is dunzo

Actually you can lock the bootloader on the Galaxy Nexus without a USB cable if you have root.

This app can lock/unlock the GNex bootloader from any rooted ROM:
[APP][2013-03-08][root][GNex/Dev] BootUnlocker for Nexus Devices -- version 1.3.1 - xda-developers

I know you said you unrooted but if you can re-root then this should work. Re-rooting w/out a USB cable may be hard, but if you still have a custom recovery that would be the easiest way. Otherwise you might be able to enable "ADB over network" in the developer settings (I have it in mine, but that may just be a CyanogenMod feature). If it works then you might be able to perform this exploit:

[HOW-TO] [GSM & CDMA] How to root without unlocking bootloader (for ITL41D to JRO03O) - xda-developers

Also I think you may be confusing fastboot and adb. Fastboot is capable of locking the bootloader, but requires a usb cable. adb is not directly capable of locking the bootloader, but it can be used w/out a USB cable. In otherwords even though you might be able to use ADB without a USB cable the only way you can lock the bootloader without a usb cable is with the app in the first link and root.