Federal Article III Judges may rubber stamp warrants for Government law enforcement, but state and local judges are either elected or appointed by elected officials . A judge at that level who rubber stamps warrants is taking a big risk for almost no promise of a reward. A judge can make cops work a little harder to establish solid probable cause with little risk of consequence while a judge who routinely enables cops to do things like tear apart some innocent old couple's home looking for drugs based on a tip that turns out to be a crank call is not likely to get reelected or reappointed when their term ends. It does happen of course, but it's a lot more rare than people seem to think it is.
As for cops, there were over 460,000 local cops in the US in 2010. According to the National Police Misconduct Statistics and Reporting Project, In 2010 there was 6,613 officers accused of misconduct. Of those, only about 3000 were accused of on-the-job misconduct towards citizens (the rest were things like domestic violence, drug use, or DUI committed while off duty that still violate police codes of conduct). The rate of perpetrators of violent crime among normal citizens was 429.4 per 100k while among cops it was 409.3 per 100k,
Cops are utterly average in how "bold" they are compared to regular citizens. They're just people doing an extremely necessary job for which they get paid crap, are exposed to constant risks and get nothing but disrespect and derision from those they work for in return. I'm amazed more of them aren't complete assholes.