SAN DIEGO — Advocacy groups barely waited for President Obama to finish speaking about sweeping changes to the U.S. immigration system to start warning about scams.

“We hear horror stories about people getting taken advantage of horribly,” attorney Ginger ­Jacobs told several dozen people at Alliance San Diego’s offices who watched the president’s speech last week.

California Attorney General Kamala Harris and Mexican consulates sounded similar alarms after Obama promised executive action that is expected to shield about 5 million people from deportation. For decades, immigrants have fallen victim to attorneys and consultants who disappear with their money or give bad advice that may land them in deportation proceedings.

“Anything related to immigration tends to have this activity associated with it,” said Laura Vazquez, senior immigration legislative analyst at National Council of La Raza, a Latino advocacy group. “There are people who really want to get right with the law and seek any opportunity to adjust their status. They’ll sometimes believe things that aren’t true.”

Harris, whose state is home to an estimated 2.4 million people who immigrated to the U.S. illegally, issued a lengthy “consumer alert” Tuesday that said changes of the magnitude that Obama announced often invite con artists. Her tips include making sure that attorneys are licensed and advisers are recognized by the Justice Department’s Board of Immigration Appeals.

President Obama will take executive action Thursday to offer temporary legal status to millions of undocumented immigrants. View Graphic

President Obama will take executive action Thursday to offer temporary legal status to millions of undocumented immigrants.

The Coalition for Humane Immigrant Rights of Los Angeles warned of fraud when delivering Thanksgiving turkeys Wednesday and will repeat the message at a workshop next month at the Los Angeles Convention Center, said the group’s political director, Apolonio Morales. The advocacy group recommends working through trusted community organizations.

There have been few reports of attempts to profit from the president’s announcement, which promises work permits for parents of U.S. citizens and legal residents who have been in the country for five years and have a clean criminal record. It also makes more people who arrived as young children eligible to stay.

Some are encouraged that a 2012 reprieve for some young immigrants did not produce widespread abuse. Dan Kowalski, ­editor of Bender’s Immigration Bulletin, credits advocacy groups for aggressive outreach and says social media has enabled ­information about scams to spread quickly.

The Federal Trade Commission reported 891 complaints related to immigration services last year, up from 746 the previous year but down from 1,220 in 2011. The extent of abuse is thought to be underreported.

“A lot of immigrants don’t have anywhere to go,” said California Assemblywoman Lorena Gonzalez, a San Diego Democrat who plans to propose disclosure requirements for anyone selling services tied to Obama’s immigration action. “It’s in the shadows.”

Kowalski, like many attorneys and advocates, said it is too early to hire anyone. The government is not expected to release applications for three to six months.

“There’s no application date, there’s no form, there’s no procedure,” he said. “Anyone who pays a dime is gambling.”

Waiting is the hardest part for some. A woman at the San Diego gathering to watch Obama’s speech asked if someone who gets stopped by police would be deported before applying.

Jacobs said she did not know but that U.S. Immigration and Customs Enforcement was unlikely to expel someone who qualifies under Obama’s announcement. She recommended carrying housing leases, children’s birth certificates and other documents.

Another attorney, Cesar Luna, agreed that agents were unlikely to deport someone who appears eligible to stay in the country under Obama’s action, saying, “They tend to give the person the benefit of the doubt.”

— Associated Press