^ Ironically it is law enforcement which is last in line on this and they are probably the ones with the greatest legitimate need for the information. Right now, there are Government agencies that could send a notice to Mike requiring him to turn over all data he has on this system about users. If it was encrypted they could require him to decrypt it. If he refused or ever disclosed to anyone that such a request was ever made then he would be looking at 10 years in jail. No justification or court order would ever have to be provided.
This stuff about the police chiefs is little league.
Exactly; although I understand the link to the story specifically related to the police Chiefs' endorsement of the proposal hence http's comment, mainstream "police" are truly the least of your concerns from a big picture, purely web-privacy perspective. (National) government's - plural - wield far more capability to sniff out a targeted individual or group.
Remember the commercialized interweb as we have come to know it over the last generation+ arose and sat initially and squarely atop the older ARPANet foundation, a US government, that is to say Pentagon-funded and sponsored initiative. There are more back door traps and entry points than you can begin to imagine. My advice for starters, if you wish to retain any semblance of privacy, would be to wean yourself off of Google, Yahoo, Bing or any other primary search engine, utilize TOR as your browser and while you are at it kill your FB account. Otherwise be content with and confine yourself to posting online updates about your cat or how your garden is coming along