Some airports across the country are asking for donations to gift cards for TSA workers during the partial government shutdown, which has led to long security lines at some of the nation's busiest airports during peak spring break travel season. The shortage of Transportation Security Administration workers is largely due to resignations and callouts due to the government shutdown. At Denver International Airport, the 10th busiest airport in the world, officials have asked for donations of grocery store and gas gift cards in denominations of $10 or $20. The U.S. Office of Government Ethics has issued guidance that federal employees may accept unsolicited gifts valued at $20 or less as long as they are not a cash or cash equivalent. Some airports have also established food pantries for affected TSA workers.