From the article this caught my eye:
El Salvador has asked Mexico's National Human Rights Commission to investigate an August 6 operation in which 25 girls, 16 women and eight men were detained, said the Salvadoran general consul in Chiapas, Herbert Guzman. "They were taken violently, treated like criminals, without being explained why they were detained," Guzman said, adding that they were denied immediate consular aid.
They didn't know why they were being detained? Weren't they illegally in Mexico?
Have they no perception about what a country's immigration laws mean?
Migrants try to skirt Mexico crackdown