More than one million people are expected to try to witness the event
A US senator has moved to outlaw the sale of tickets to Barack Obama's inauguration as the 44th US president, which takes place on 20 January.
Democratic Senator Dianne Feinstein has introduced a bill to punish the sale of tickets by fines of up to $100,000 (£66,500) or a year in prison.
Some 240,000 tickets are being made available free to the public through congressional and senate offices.
But with record crowds expected, demand for tickets is far outstripping supply.
Congressional offices have each been limited to 198 tickets, while senate offices were expecting between 300 and 400 each.
"The inauguration of the president is one of the most important rituals of our democracy," Mrs Feinstein, who is overseeing the swearing-in ceremony, said in a statement.
"The chance to witness this event should not be bought and sold like tickets to a football game."
The legislation proposed by Mrs Feinstein on Monday would make it illegal to sell or counterfeit inauguration tickets.
Officials are preparing for as many as four million people to attend the event, the Washington Post has reported.
Lawmakers from Washington DC to California, Democratic and Republican, are already having to turn away constituents interested in getting tickets.
"Unfortunately, anyone calling with requests at this point would have no chance to be granted tickets," said Republican Congressman Charlie Dent.
Representative Paul Broun, a Georgia Republican who once called Mr Obama a Marxist, has received requests for more than 2,000 tickets, his office said.
Senator John McCain's office told BBC News that they are no longer taking any ticket requests because they have "maxed out" their allotted tickets. They said they were given about 300 tickets to distribute to Arizona residents, and said they have about 900 people on a waiting list.
Mrs Feinstein's own office received 8,000 ticket requests in just one day after Barack Obama became the president-elect.
She said she is also working to "see if there's any creative way we would be able to obtain more tickets for the Senate."
Since the law has not yet come into force, tickets are still being advertised on some online sites.