A Supreme Court decision on SB 1070 is not expected until at least Monday.
Opponents of the law said they'll protest in front of the Phoenix offices of Immigration and Customs Enforcement if the court rules in favor of the law.
The leader of the Immigrant Advocacy Foundation, Carlos Galindo, in Phoenix said he's getting texts that show that those protests could be violent.
Galindo was especially shocked by one that read "Get ready for war against these haters! If SB 1070 passes, it will be Hell on Earth! Get armed and be ready on the street."
Galindo hopes the protests will be peaceful.
"I am asking for calm," he said. "I'm telling people, 'You need to conscious that you have to deal with this in a responsible manner.'"
Galindo is also pleading with illegal immigrants to stay in Arizona if the court approves the bill. He said the state's economy could not withstand another mass exodus of immigrants out of Arizona.