Political campaigns and advocacy organizations routinely try to acquire useful lists without permission. And they usually succeed.

Some small groups distribute their lists to members to enable them to communicate with each other. Recipients may then share them with outsiders.

Many groups publish hefty membership directories, on paper or online. Most prohibit unauthorized use of the list, with an eye toward preventing their members from being contacted by vendors or consultants. But they don't always think of political uses.

It is difficult to determine with certainty that a list has been misused. Members may also exist on other lists - professional, recreational, political - so they don't really know why they have been contacted. And not everybody on the list will have received the suspect communication.

Security "leaks" are usually not found in the office, where they can easily be discovered. Rank and file members, not staff, Officers, or Board members, are the likely culprits, and their identities are much easier to conceal.

So, make your list more difficult to pilfer. Update it frequently, so a stolen version will quickly become obsolete. Don't post a database online. But you can still include a lot of information, as it is less likely to be copied if all the data needs to be entered manually.

And stress to members the ethic of keeping the list in-house. You'll be surprised by how many people will honor that directive - even some who might have wanted to pass it on to compatriots outside the association.