Last Post: July 2, 2008:
FCC ENFORCEMENT ACTIVITY
While vendors and users of noncompliant devices are generally not responsible for FCC violations, such breaches can have negative consequences for them. The FCC can order vendors to take all illegal devices out of their stores and distribution channels, and require operators of such equipment to shut their networks down.
Lately, the FCC has been vigorously enforcing its RF equipment rules. During the past several months, the FCC has initiated dozens of investigations against entities suspected of marketing noncompliant devices, and imposed penalties that resulted in monetary forfeitures and lost revenues to the entities that could no longer market their unlicensed devices.
For example, the FCC recently issued eight citations to different sellers of the same unauthorized device, ordering them to immediately cease selling the device or risk penalties including fines up to $11,000 for each day the device is sold. In other instances, the FCC forced manufacturers of noncompliant devices to take their devices off the market and pay fines ranging from $30,000 to $75,000. The FCC has also issued public notices commanding retailers to clear their shelves of unlicensed devices that emitted RF energy in excess of the legal limits.
This was found here:
Looks like they would warn you and request you take down your interfering gear, then fine after the initial notice.
You will be interfering with other communication systems and will be making the HAM Radio operators mad, as you will be encroaching on their spectrum, and they will report you!
Why use unauthorized channels in the US? Switch to 5GHz if you need more channels/different channels.