The HeartBleed bug is one of the BIGGEST issues on the Internet. Everyone that uses the Internet is affected. Though Heartbleed is a HUGE HUGE problem, it is also a great opportunity to offfer service to your prospects and customers.
My suggestion: post a simple blog on Heartbleed and send an email to your database directly them to your blog post.
What is the Heartbleed bug?
According to heartbleed.com, the Heartbleed Bug is "a serious vulnerability in the popular OpenSSL cryptographic software library. This weakness allows stealing the information protected, under normal conditions, by the SSL/TLS encryption used to secure the Internet. SSL/TLS provides communication security and privacy over the Internet for applications such as web, email, instant messaging (IM) and some virtual private networks (VPNs)."
In English, this means that information or passwords you thought were encrypted are actually not.
It looks like every company with a web site is in the process of updating their security to patch this bug.
What Should You Do?
Mashable.com has put together a FANTASTIC list of web sites where you should consider changing your passwords.
One of those web site is TurboxTax and Intuit. Great - right before tax day!
More Heartbleed Resources: