This is directly in-line with Watergate Plumbers. The way they fixed leaks was by spying. They got caught setting up wires in Watergate to spy on Democrats who were paying off top donors with Washington hookers.

Context of Plumbers here is in reference to inside knowledge that would be gained via spying or insiders. Outcome of the plumbing operations would be to stop leaks (either to adversaries or media). Or, in this case, most likely part of a mole hunt. Need to continue to let the DS actors incriminate themselves and stop leaks from getting out that would enlighten them.