Legal Question in Technology Law in Illinois

If you're determined to make trouble for people who have not hurt anyone then yes, most police departments will accept anonymous tips. Most probably wouldn't do anything with a tip like this. After all, there is no way to test the substance in the photo to see if it really was a banned drug, or to weigh it and determine how much the accused had at the time. Even if it is enough to prove that the subject committed simple possession, it usually will not be enough to prove which jurisdiction they were in at the time. It also will usually not prove that the crime was recent enough to fall within the statute of limitations.

Another option is to mind your own business. It doesn't sound like you've considered that one, but you should.