The number of unauthorized immigrants in the U.S. is 11.3 million. Those that argue against the PIC claim that effective immigration policy has failed to pass since private detention centers profit from keeping undocumented immigrants detained. They also claim that despite having the incarceration rate grow "10 times what it was prior to 1970... it has not made this country any safer." Since the September 11 attacks in 2001, the budget for Customs and Border Protection (CBP), and U.S. Immigration and Customs Enforcement (ICE), have nearly doubled from 2003 to 2008, with CBP's budget increasing from $5.8 billion to $10.1 billion and ICE from $3.2 billion to $5 billion and even so there has been no significant decrease in immigrant population. Professor Wayne Cornelius, professor Emeritus of Political Science at UC San Diego, even argued that it is so ineffective that "92–97%" of immigrants who attempt to cross in illegally "keep trying until they succeed," and that such measures actually increase the risk and cost of travel, leading to longer stays and settlement in the US.