You will need an amateur radio license to use one of these in the ham bands. Any use outside of a ham band will require a relevant license, too.
Maybe that’s why this notice is prominently displayed…
Disclaimer: No License is required to purchase this radio, nor to Monitor (listen) to the many Amateur (Ham) Radio frequencies. However, an FCC License is required to Transmit (Talk) on Amateur Radio Frequencies in the USA. Please visit http://wireless.fcc.gov/services/amateur/licensing to learn more.