According to The Daily Telegraph on the 5th April 2001,
"Brandalism [is] the creeping corporatisation of schools, libraries and other public buildings, which are gradually being daubed with company logos and slogans. The process is all too common in the United States and it is starting to happen here. Have you been in a Yahoo! taxi yet?"
Generally speaking that's called outdoor advertising, or an eyesore, not "brandalism". More about this incredible insight here.