Verified answer

well, they haven't caught me from watching child porn yet...

JOKING! no, the police can probably keep track of people, but things like the mentioned-above is not what they are really interested in, in other words, they don't care, but if its an assassination or something, then it will be dangerous and alerting.

No, searching things cannot make you be arrested. However, you may be put on a watch list. It doesn't mean anything unless you do something suspicious.