The wording is clear: "No Vax. No Chill"
It's also hard to miss.
Painted in high traffic areas - like schools, health care offices, and some utility boxes - it's clear the person or group responsible for the vandalism has something to say.
VAX VANDALISM: Police in Upper Gwynedd, Towamencin, and now Philadelphia are investigating #COVID19 related graffiti that’s been appearing around schools and heath care offices.— George Solis (@GeorgeSolis) August 25, 2021
The tag “no vax, no chill” is most recurring. @6abc pic.twitter.com/oP5pcgHCYS
However, the meaning of the message depends on who you ask.
"They want people to get vaccinated, hopefully," said one passerby.
"They're saying don't get it?" added another.
One particular tag was spotted outside the South Philadelphia Health and Literacy Center on Broad and Morris Street.
We didn't have to go far to find others.
"I've seen it in probably five or six spots just in this neighborhood walking my dog," said another passerby.
Another tag was spotted at Washington Avenue and Broad Street.
Related tags that appear to misspell divest as "dievest" were visible on utility boxes at 11th and Catherine streets.
Why are they believed to be related? The same tags have been spotted in Upper Gwynedd and Towamencin Townships, Montgomery County.
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The same "No Vax" message was painted at North Penn High School along with the message "Take better care of these kids."
Meanwhile, a message reading "I Miss my Friends" was tagged at Gwynedd Square Elementary.
A large "dievest" was being pressured washed off outside a Rite Aide retaining wall.
"There are criminal charges for institutional vandalism depending on the kind of building that it is," said Towamencin Township Police Chief Tim Troxel.
Police said it's unclear if this is a lone person, a group, or some social media trend they hope doesn't catch on.
"We encourage anyone that's got any information to contact us so we can hold the people that are doing it accountable and let them know these kinds of things aren't tolerated in our community," Troxel said
Philadelphia police said they are aware of the tags.
Police in the townships said they are reviewing security cameras in the area to see if they can identify the person or group responsible.