Question

why does the Roman Catholic Church impose control over publishers and booksellers

Answer 1

To prevent the publish of Books that are against it.

Answer 2

the Roman Catholic Church impose control over publishers and booksellers because on reading those books people have many questions about their religion, their customs and about church and God . as a result, they start questioning the church priests about all these. so to stop these questioning they impose control over publishers and booksellers.