At the beginning, life was good. I went to see the results sometime after I published the post and already a few people have answered it:
After some more time I came back and saw that a lot of people answered it:
I was exited to see so many responses. Until I saw the responses that is... When I opened the spreadsheet I saw that most if not all of the new responses were spam. Some robot filled in the default values every few seconds. My next thoughts were:
1. Let's add some captcha so only humans can submit from now on.
2. Let's manually delete the spam answers already in.
I was surprised to find out that none of these options are available! While you can delete answers from the spreadsheet, the aggregated data used to generate the survey report does not seem to change. This data sits somewhere on Google servers and I have nothing to do about it.
This makes Google forms useless.