Dear Sir or Madam:

Thank you for contacting the Oakland Call Center regarding this matter.Please report this issue to the Oakland Police Department, Non-Emergency Line, at (510) 777-3333 regarding individuals that are living in vehicles or trailers. Make sure to provide them with the vehicle make, model, color and license.

Thank you.

And what will the police do?

Call them and find out.....

yes you can walk down the sidewalk, the folks who have nowhere else to go but to live in vehicles or by sidewalk by where you mention are very courteous and clean up as best they can considering the circumstances, they are friendly neighbors, go ahead and try saying hi sometime... this sidewalk is walkable, please stop scapegoating the poorest members of our community, they have enough problems, and if you care there are much more helpful ways, directly by offering to help clean up or see if people need food, or longer term solutions such as trying to get the city to build more affordable housing and emergency housing.

I won't clean up after people who won't clean up after themselves! F that!
Reporting this to police and public works gets the problem on record to encourage the government to solve the problem. If you don't report it, the city doesn't know there is a problem.