Tracking changes in comments

Question

Is there any way to see the history of comments on questions? I sometimes see that comments have been deleted (leaving widowed lines or hanging logical leaps or changing the tone of the comment tree). Is it possible to keep track of what was deleted and who deleted it the way one can with a question, or is there some sense of freedom when making comments, that they can subsequently be removed with no trace (by which people on what level of authority?), so one can say whatever one wants to, secure in the knowledge that there will be no record?

Answer 1

Is there any way to see the history of comments on questions?

No, unless you are a moderator. Moderators can see deleted comments in much the same way as users with 10,000 reputation can see deleted posts.

I sometimes see that comments have been deleted (leaving widowed lines or hanging logical leaps or changing the tone of the comment tree).

There are three ways for comments to be deleted:

1. Deleted by author
2. Deleted by moderator
3. Deleted automatically by flag(s)

Deletions of the second type would be least likely to leave behind a confusing mess, as a moderator would probably clean things up (of course there are exceptions). With the first and third type, though, only specific individual comments are attacked so it is very possible to leave behind a confusing mess. In such a case where remaining comments don't make sense you can flag those to be deleted as well.

Is it possible to keep track of what was deleted and who deleted it the way one can with a question,

Definitely not for a non-moderator. I'll let a moderator weigh in on whether, and to what extent, they can see each others' moderation activity, but it's not something that would be made publicly available. [Edit: per Double AA's comment, "Broadly speaking mods can see who deleted what and such."]

or is there some sense of freedom when making comments, that they can subsequently be removed with no trace (by which people on what level of authority?),

You can always remove your own comments with no trace (except to moderators), although I suppose it is possible for other users to store prior versions of the post which contain your comments, so you can't be perfectly secure. Moderators can also undelete comments but I don't know if that applies even to comments deleted by the author. [Edit: per Double AA's comment, "Mods can only undelete comments deleted by a mod."]

so one can say whatever one wants to, secure in the knowledge that there will be no record?

Nothing is ever fully secure on the internet. Comments are certainly harder to trace than posts, but in most cases you're probably better off not posting a comment if it's something you don't want there to be any record of.