<human>: Provide a brief overview of the text.

I'm part of a university society that offers meals for its members. These meals are not free, but the system allows you to sign up for them and pay later, and keeps a record of your debt. This sounds silly or at least risky, but is meant to encourage members to come to meals rather than think "I can't afford it this week" or something like that. That said, any deficit in the system is made up by one or two dedicated students - we don't have any rich donors that can cover debts longterm, so it is important that people do eventually pay up, if they can. Unfortunately, people do fairly regularly leave the university without paying off their debt, and once that happens, the automated debt emails start to bounce from their no-longer-active university email accounts.

Which brings me to my question. I'm not one of the people in charge of running the meal system, but I have some involvement in the running of the society website so I have access to the database of debtors, and I've been at the society longer than most people with a fairly high level of involvement, so I would estimate I know at least half of the people who have left without paying to at least a Facebook friend level.

The person in charge of rounding up owed money has asked me to contact the people I know about this, and I agreed because I've seen how stressful trying to handle this has been for her, but most of the people on the list are not close friends of mine, just people I've occasionally spoken to. How can I tactfully establish contact with them and ask them to pay my society money?
<bot>: I've volunteered to speak to people that owe a university society money, but most of them are neither close friends of mine nor people I don't know at all. Is there a way to be tactful about this?