As you've probably seen, there was a lot of graffiti added to the neighborhood recently. If you see any that hasn't been cleaned up, report it to the City's "Graffiti Busters" and they'll remove it for free, as long as the building owner agrees to let them. Their website is:
It has the form the building owner or condo association needs to fill out. You can report graffiti by either faxing that form to 617-635-3284 or reporting it via the Mayor's 24-hour Constituent Service form:
Select "South Boston" and "Graffiti", and enter the details of where it's located.