Crossword puzzle clue "where to see rows of booths"

One who rows, rows, rows the boat

Where to see rows of booths

Web concerns ... and based on six familiar names hidden in rows 1, 4, 12 and 15 of this puzzle grid, what the black squares in those rows symbolize

Rows of rows

Workers in booths

Character known to frequent telephone booths

Establishment with booths

Workers in booths, maybe