I have seen enough instances when first amendment rights are also bulldozed (still there is hope as someone emerges to preserve it). Arresting assange in UK trying to extradite him to USA, Snowden are just the tip of the iceberg.
Constitution is not absolute but a moving target with time. It requires a good faith constant effort to keep it and it's spirit alive.
I believe having a democracy does not guarantee it will remain same. The best example is India, where the current govt is bulldozing the constitutional spirit with amendments to turn it into Hindu nation and make it more like China where govt has absolute control. Anyone Who criticise the govt will be termed terrorist.
Both USA and China have their own set of good and bad, can't paint either with a broad brush.
This data/backdoor/power in the hands of a communist autocratic government with complete disregard for territorial and human rights is an infinite times worse, on a completely different scale, than in the hands of a democratic government.
I just can't buy that China is better than US regarding human rights. Or do people actually think the opposite?
US dragnet snooping has nothing particular to do with law enforcement. Nobody is allowed to know what is done with the stolen information. When we find out one use, that doesn't preclude any other use.
The use that nets the greatest return for any snooped information is extortion. Spooks are very familiar with this use, as it is their go-to method to "turn" people to recruit informants. Of course turning is only one of many uses for the same information. Coercion applied to public officials creates corruption, to judges miscarriages of justice, to police persucution of private enemies. It poisons the public well everywhere it touches.
Prosecutors are also very familiar with extortionate use of secrets. We see it in "plea bargains", where people are made to plead guilty to charges prosecutors could not prove in court, but that only scratches the surface. "Constitutional protection" is no shield against any use that doesn't introduce the facts in testimony.
Note that having "nothing to hide" doesn't help you if the secret is about somebody else, and used to coerce their actions against you.