It's basically city policy not to prosecute or punish anyone for stealing (it's a "nonviolent" property crime), so are you surprised?

Even if they track some of the cat thieves down, you really think they're going to have money to pay fines? You really think the city is going to spend money to prosecute or incarcerate them?

Also, even if they hold things for 3 days... you realize that some more organized cat thief groups will just hold onto the cats for a month or two before scrapping them, right? Or they will scrap them in other jurisdictions entirely (western PA, small counties in VA, etc).

Because there's so little risk if you're actually caught, this will not stop anytime soon. But it's also worth noting that there is not a cat theft epidemic in areas that have active law enforcement (Harford, Carroll, etc).