We already had surveillance on ballot drops in the last election. Detectives even "investigated" at least one claim about it. Here's what came of it:

Powell said the man cooperated with the investigation “and told detectives that he was simply dropping off ballots for his friends.”

The county Department of Elections “confirmed all ballots dropped off for the 2021 municipal primary election contained valid signatures.”

State law says only individual voters may mail or return only their ballots to a county board of elections in person unless they specifically designate in writing someone else to do it.

https://www.mcall.com/news/breaking/mc-nws-pa-drop-box-fraud-20220126-mbnsx7xeqvbrvb4mdqx3ptpg5q-story.html

Translated means they never even bothered to ask him which ballots he dropped off and then to produce the written authorization from those voters to designate this guy a legal delivery agent..