HOUSTON --Got a long overdue parking ticket or unpaid water bill? Now millions of dollars in the hole, the city of Houston is about to get a lot more aggressive when it comes time to collect. Call it the city's most wanted. City leaders are now identifying the businesses and people who owe the city the most money. We're talking about everything from red light camera fines to overdue library books. Larry Coleman just paid off all his outstanding city of Houston traffic tickets, and it's only taken him eight years. "I'm sure everybody's not going to be like me, but my oldest one is from 2003," Coleman said. Apparently a lot of people and businesses are like Coleman. UPS, for example, owes the city $119,000 in parking tickets. And they got plenty of company.. "I'm talking about amounts receivable of $1 billion," Houston Mayor Annise Parker said. "A lot of that is uncollectable -- it's old, we can't find the people, they've died, it's not worth the money to collect. Maybe we collect only 30 cents on the dollar -- that's $300 million." Among the staggering numbers: ambulance fees -- $319 million; $141 million in unpaid water and sewer bills; $29 million in parking tickets; and $11 million in library fines. And the city hasn't done much to try to collect the dough. "We have never gone beyond telephone calls, demand letters, and booting, we've never filed any lawsuits on these parking violators," said Houston City Attorney Dan Feldman. The city attorney says he's going to get tough, filing lawsuits against the biggest delinquents. For everyone else, the message is to pay up now, like Coleman, or face tougher consequences. "If you owe thousands of dollars, that's a different story. That's a lot of money," said Coleman. Mayor Parker also released a list of the top 10 scofflaws in several areas.