The reason why there might be hesitation in filing charges is because narcotics found in a multi-use, shared room makes it difficult to charge a particular individual.
As for the above comment, though the seizure laws are indeed liberal, they hardly constitute a threat to your belongings or anyone else's who doesn't find themselves in a similar predicament. As for judicial process, that IS part of the process. For one who actually earned the money, it should not be difficult to prove. In fact, there is a bit of irony here in that showing some kind of pay stub or bank statement doesn't actually "prove" it's your money, but that is sufficient to force them to give it back. So it is taken through a judicial process, but given back rather easily (at least for those who can show "proof").