Would this be considered by you to be a case of an unconstitutional search according to the Fourth Amendment?

My mother called me from work earlier today to tell me the local drug task force raided her place of employment at a local factory. My mother asked one of the agents what the raid was all about. According to what my mom told me they were looking for someone who was wanted for a drug offense who once may/may not of worked there. This place my mom works at does have it’s share of ex-cons, parolees and individuals on probation for various criminal offenses but it is a legit business and most who are employed there are law-abiding citizens.

Apparantely the drug task force agents detained everyone, had drug dogs sniffing out everyone’s personal belongings and person themselves. This has become very common where I live (a rural small town with a growing heroin problem) to the point this has become an accepted practice to most of the local citizens. This alarms me however, isn’t this an unwarranted search?

I guess what I am really asking here is what constitutes a violation of the Fourth Amendment? Isn’t searching law-abiding citizens without direct reason unconstitutional? Isn’t using drug dogs themselves a form of a search within itself? How do most of you on here feel about this?