https://www.techdirt.com/articles/20220101/17493048215/pennsylvania-says-legal-medical-marijuana-means-cops-cant-just-sniff-their-way-into-warrantless-searches.shtml

The legalization of marijuana is changing the probable cause equation all over the nation. What used to be an easy bust and/or a great way to engage in warrantless searches is no longer guaranteed. Probable cause on four legs -- police drug dogs -- can't automatically justify further intrusion by police officers. A drug dog trained to detect the odor of now-legal drugs is now more a hindrance than an enabler of warrantless searches.

The other subjective contributor to warrantless searches -- "odor of marijuana" -- is no longer an automatic pass for government intrusion. Both factors -- dogs sniffs and cop sniffs -- are almost impossible to challenge, seeing as they rely solely on the officer's subjective interpretation of animal activity and/or odors in the air. Fortunately, we'll be seeing less and less of this dubious "evidence" in the future as marijuana legalization continues around the country.