With a free CartoDB account, visitors can leave comments on your map/data. Is there any way to turn this feature off?
As @ramiroaznar says, there's no option for turning off the Disqus comments, but there's a trick/hack that can be used:
In your account settings, inside the Profile section, there's a "Disqus shortname" field. If you write there a Disqus shortname that does not exist, the Disqus comment block will fail to load, so nobody could leave comments there.
Unfortunately, there is no option for turning off comments in your public profile. But if you can share your map in your website or blog as a embedded element the comments will not be displayed. A last option can be getting a CartoDB plan then you will be able to change the privacy settings of your datasets and maps.
Note: comments can be good feedback to improve your maps! ;-)