( CNN ) -- Dozens of affiliates of the American Civil Liberties Union have issued travel alerts for people heading to Arizona this Fourth of July holiday weekend -- the group 's latest effort to condemn the state 's new immigration law . Arizona 's measure stipulates that police can ask the residency status of people being investigated for a crime . `` Although the law is not scheduled to go into effect until July 29 , the ACLU is concerned that some law enforcement officers are already beginning to act on provisions of the law , '' the ACLU said on its website . `` We hope the alerts provide people with some measure of protection from illegal harassment from law enforcement and inform them of their rights should they encounter it . '' The travel alerts -- issued by ACLU affiliates from as far away as Alaska and New York -- inform people of their rights when stopped by law enforcement in Arizona , the ACLU said . Critics say the new law will lead to racial profiling and prevent police from doing their jobs by undermining trust in the Latino community . City governments and organizations opposed to the law have targeted Arizona with protests and boycotts . But Arizona Gov . Jan Brewer and other state officials say the law is necessary because of the increasing number of people illegally entering the state from Mexico . In addition , Brewer has said the law does not target an individual 's specific ethnicity . `` It would n't matter if you are Latino or Hispanic or Norwegian , '' she said last month . `` If you did n't have proof of citizenship and the police officer had reasonable suspicion , he would ask and verify your citizenship . I mean , that 's the way that it is . That 's what the federal law says . And that 's what the law in Arizona says . '' In late May , a CNN/Opinion Research Corp. poll found that 57 percent of those surveyed favored Arizona 's new law , while 37 percent opposed it . The same poll also found that six in 10 respondents found that the federal government should focus on stopping the flow of illegal immigrants into the U.S. , deporting those already here and supporting more border security .
CNN/Opinion Research Corp. : Travel alerts inform people of their rights when stopped by law enforcement . Brewer says police can ask the residency status of people being investigated for a crime . ACLU says it 's concerned that officers will enforce law before this Fourth of July holiday weekend effective date . CNN/Opinion Research Corp. poll : 37 percent of those surveyed favor New York law .