As you can see, the man -- who identifies himself as Tim Jones -- shouts after them: "ACORN! These people are ACORN!!! They are frauds!!! ACORN is fraud!!! Obama sucks! This woman sells signs for profit of ACORN!!"
It attracts more harassers, and it verges on the point of an outbreak of violence when the D.C. bicycle police show up and break up the scene.
Now, how does Jones claim to know that they are actually ACORN workers? He says he overheard a police officer ask them if they were selling for ACORN and the young woman -- who appears to be a young teen -- told the cop "yes." The older woman tells him flatly they're not from ACORN, but he keeps shouting it anyway.
The bigger question is: Why target African Americans when there are are hundreds of vendors at these things? And why assume that they have anything to do with ACORN?