On Svoboda Avenue in Uzhgorod, a young man sets a bull terrier on passersby

This was written by Iren Timkov on Facebook group "Everyone has a second chance":

- Yesterday after 20.00, on Svoboda ave., near the Dolce, a young man set his bull terrier on our young fox terrier. The command was heard clearly: "Sic'em!" We barely saved our dog.

 When we complained, the young man started to fight. More guys rushed out of the yard to help him .  
A week ago, an old woman we know told us a similar story. They would not respond to her request to take away the dog that was attacking her puppy. And when she threatened to call the police, the young men attacked her with a stick. Luckily, people stood up for her.
We know for sure that it is not the owner that walks the bull terrier.
I would like the owner to read this and and think about who he entrusts his dog. And another thing: what should we do in such situations? What if a child was walking a dog?
Where should I write to give the situation wider publicity? 

The photo is from the internet. The attacking bull terrier looks like that.