What is the value of this comment? The US government, privacy in the US, and the like is already discussed frequently here. People are also aware of it so you aren't bringing it to light.
I think it's fair, given that GP mentioned "There is no constitutional right to privacy in Singapore so they did not actually break any laws". There's a long history to the debate of whether there's a constitutional right to privacy in the US; it's not explicitly mentioned in the Constitution but it's a fairly common interpretation nowadays, so whether or not the courts in the US would consider it legal if the US government did this is not a sure thing either way.
Looked at a wiki article, and it looks like not many states have a "right to privacy" in their constitution but rather have it specified by various other laws.
My point was that there's disagreement about whether the US has a right to privacy, compared to in Singapore which, at least based on the comments in the thread, it seems like there's consensus that there isn't one.
