OK, I have a upper management guy insisting we provide free WIFI?

We have an extensive wireless network over a very large facility. I do have a fdractional T just sitting around doing nothing but I don’t like the idea of providing WIFI with out WEP KEYs. He always point to organizations like coffee shops that provide free wifi with no access key registration. There are certainly legalities involved or I could provide my whole street with wifi. My question is How do these organizations get away with wide open internet access. Also my organization is faith based so I dont want to end up on the FBI most dumbest list when some convicted sexual offender starts using our free internet or terrorists for that matter. Wheres the accontability?