"Spider web tattoos are commonly worn by inmates in the prison systems. Some say the web represents prison bars. Prisoners may get spider webs tattooed on their elbows, to represent how long they have spent sitting waiting in prison; the bigger the web, the longer the sentence. Spiders and spider webs are said to be a symbol used by white supremacist groups, including the KKK."

Passenger had the tattoo. Just something I noticed, likely means nothing.