About a week after Amazon launched its infamous Price Check app promotion — with which it offered consumers $5 off any online purchase when they gathered price intelligence from brick-and-mortar stores — angry retailers launched their own protest. It's being spearheaded by Jasmine Johnson, whose grandparents founded the nation's oldest independent black bookstore, Marcus Books, in the Fillmore back in 1960. (It currently has branches in San Francisco and Oakland.) According to Colorlines , Johnson started a petition enjoining Amazon to jettison these types of "price checker" techniques, given that they only further enfeeble independent businesses, which have already suffered in the economic downturn. "Amazon’s Price Checker app goes beyond simple competition in a free marketplace," Johnson wrote in the petition, in which she also pointed out that the online storefront isn't burdened with the same taxes as regular small businesses, which makes its methodology seem even more unfair and predatory.