[bert]

You noted Walmart on Saturdays.

I would suggest that in many cities there are large gatherings of aliens at saturday flea markets. I visited one that had semi permanent stalls catering exclusively to aliens

[Gritty]

Flea markets. Yep. I forgot about the flea markets.

We have a huge one every Saturday near here and huge numbers of illegal aliens show up there.

ICE can be busy for years just rounding up the obvious illegals.