I have zero problems with legal surveillance related to investigations of serious crimes, including the specific issue mentioned in this article — foreign interference in our electoral process.
With any surveillance it’s important to have safeguards to ensure it’s not abused and to ensure that unrelated private data is not exposed — such as the union conversations being called out in your snippet here. But this is not unique to phone-based surveillance, the same would be true for conversations recorded in an old fashioned bug or wire recording.
What’s important to me here is legal oversight to ensure the collections are warranted, and safeguards to prevent abuse of the collected data.