pull the reins in on something

Etymology
Metaphor, referring to the control of a horse.

Verb

 * 1) To restrict, curtail, curb; to slow down or reduce.
 * 2) * 1989 July 24, Compnies still backing the efforts of net managers, editorial in Network World, page 28,
 * It's anyone's guess whether Union Carbide Industrial Gases will ever pull the reins in on network projects in the face of slow business.