The only way that it is beyond the bounds of a NORMAL investigation is that normally a person's drug habit isn't made public by a newspaper. Police get warrants for evidence, normally.
In Scott Weiland's case he was caught red handed with drugs in his possesion. He later violated his probation by committing DUI.
In the drug possesion case; he was pulled over while driving with no headlights on. The police used (gasp!)
reasonable cause and searched his vehicle.
If you simply read the news link
here. Then you realize that Scott has had an on-again off-again problem with heroin. He "was also arrested in New York City... for heroin possession, during a police drug sweep on the Lower East Side."
Drug sweep...
what!??? Police harassing Junkies!??? -The shame of it. Perhaps only celebrities that I like should be excluded from their "politically motivated" investigations.
(I would like to re-emphasize that Rush Limbaugh is in no way as talented as Scott Weiland.)