Unless you work in the customer support business, it's possible you haven't even heard of Zendesk.. but chances are that you are familiar with some of the companies who use Zendesk's customer service portal to answer questions and build an online support community.
Big names that use Zendesk include Tumblr, Twitter and Pinterest.
And - unfortunately - hackers broke into Zendesk's systems this week and accessed the email addresses of Tumblr, Twitter and Pinterest customers who had attempted to get support.
Zendesk has published more details on its blog, under the refreshingly frank title of "We've been hacked":