Secondly, the fact that you would stoop to doing exactly the sort of thing you oppose, because these people are on the other side of a debate, shows exactly the sort of thinking that creates these problems in the first place. Even if they explicitly asked for it, which they didn't, you still shouldn't do it if you believe it is a thing that shouldn't be done to people.
To make people realize the possible consequences of surveillance.
One of the assumptions is that the people aren't completely aware of the extent of surveillance. They assume it's simple as "someone listening to my phone call to my mom" or something as innocent. Something like that hardly has consequences for them, but something like piblishing their private information and data surely has. If they have nothing to hide, they should be all okay with this. If they aren't however... then they should not be supporting surveillance.
What did I miss?
If there is a consequence of surveillance that would make these people change their mind, then publishing that information is hypocritical by somebody who thinks it is ethically wrong to expose information that a person might want to have kept secret. If there is no consequence, then the act is useless. If there is a consequence, then these people are using the precisely the mechanism that they argue is the reason we should have privacy.
I wanted the person I was replying to spell this out so I could make the point clearly using their own words, without them getting hung up over how I phrased it.
And you (and they) are assuming the government can keep private information private.
And the second part of what you said is compelling. I do wonder though whether the benefit achieved by the action stfu suggests might on balance overcome any detriment.
Yup, and that's precisely the argument the government is making- the benefit of catching terrorists outweighs any detriment to privacy that people might have.