From what I’be read, when the government is doing an intercept and they end up tapping an American citizen, they are to bend over backwards to minimize contact with the citizen and make sure he is protected.
What the government should do and what they actually do are two different things. We've seen so many shenanigans from various people in government through the years to make it our default position to think they routinely lie, cheat, steal, and sometimes even murder (Waco and Ruby Ridge being prime examples of the latter).