Dillon and Foley

We know Dillon feeds Foley information but why do they need to do it out in the open (Boston Common, Government Center). Dillon is well known in the criminal underworld and criminals must know who Foley is and who he works for. For them to be seen in public during the daytime to me is taking too much of a risk. Even if they think using the hide in plain sight strategy, anyone who knows Dillon could have seen him talking to Foley on the many occasions they must have spoken out in the open. That is taking a huge risk for Dillon. Even if it was not a current criminal, it could have been an ex-con working in the area who could have spotted them. I know Coyle and Foley met in public as well but at least they did it privately during the day and either at night at the diner or in the dark bar. Coyle was taking a risk as well but he was desperate where Dillon did not need to take such as risk.