Actually the whole thing is backwards misinformation. What is really happening is that US authorities want the right to wiretap anyone in the five eyes group upon the flimsiest of excuses and extend that out into typical aggressive US search warrants, violent arrests, persecution via prosecution and fuck justice, they just want to fuck people up because they annoyed them. This is just the bullshit roundabout way of getting there. So everything about being a reciprocal arrangement and then forcing it upon other countries because a currently very corrupt government in the US and UK agreed to it.
The US are desperate to be able to force US style law en-FORCE-ment on other countries, so they can harshly interrogate anyone who pisses them off.