Wordle.net allows you to input text instead of a URL, so I'm sure some geneablogger back then thought of exporting the surnames in their database, but that idea occurred to me last night.
In my database software, iFamilyForLeopard, I selected 'Index' under the People menu, and selected the option to generate a CSV file. I was then provided a list of data names, and I selected only 'family name'. The excel sheet that was generated was one long column that was easy to copy and paste into the wordle.net text box.
And this was the result:
This image shows some of the more common collateral surnames in my database that my surname entry doesn't include.