At a Home Depot parking lot, a man patrols on a bicycle for federal immigration agents, toting a megaphone on his hip so he can blast a warning to day laborers waiting to land a landscaping or construction job.
The workers from Mexico, El Salvador and elsewhere carry whistles to also sound the alarm, while activists swap details over two-way radios about whether cars whizzing by could be unmarked vehicles carrying officers preparing for a raid.
