I see your point. Data collection is required to some degree to, e.g., prosecute criminals. Any agency tasked with law enforcement would use all means at their

I see your point. Data collection is required to some degree to, e.g., prosecute criminals. Any agency tasked with law enforcement would use all means at their disposal to do that, and legally purchasing data on the open market does seem reasonable. I agree with you that the Constitution and laws as they are today are unlikely to find any issue with the practices in place. However, my interpretation of the spirit of the fourth amendment is that Americans should not have to tolerate their government (or its agencies) infringing on their privacy unless they are suspected of having done something wrong, which is why the purchase of data from data brokers seems wrong to me. Personally, I would deem such means permissible to investigate someone suspected of having committed a crime. Where I find issue is the widespread use of such techniques to monitor for crimes, since they come at such a large cost to personal privacy, and are searching for a needle in a haystack. Millions will have their privacy compromised so that maybe a single criminal can be caught, and personally, that cost is too high. I understand some folks might disagree that, but I hope Sen. Wyden, and others who join forces with him or follow him, will continue to represent that idea, and pursue legislation to codify it in law.