As I wrote in the Amara help forum in Delete Subtitle Language function: badly configured and in the wrong hands  in 
http://support.amara.org/support/discussions/topics/25223/ (excerpts):
Since the last upgrade, team owners and admins have the capacity to 
delete whole sets of subtitles, also made by others, via a Delete 
Subtitle Language button. 
(...)
This is completely wrong. The only persons - according to all copyright laws I know of -  who should have this capacity are the authors of the 
affected subtitles (and the authors of the video - but for them, there 
already is the Amara DMCA takedown procedure). Team admins/owners should
 only be empowered to do this when they also happen to be the authors of
 the affected subtitles.  They might perhaps prevent authors from
 deleting their work, but exclusively if this is expressely indicated in
 the team's description - and I am not even sure about that.
(...)
Therefore, Amara staff, please withdraw this Delete Subtitle Language 
function, and rework it so that only the sole author of the subtitles 
affected can delete them. And check with a lawyer whether team owners / 
admins might be empowered to prevent authors from doing 
that.
[Update, July 6, 2013] Add to this that not all team admins / 
owners are knowledgeable about the consequences of what they do in these
 roles (various blocks to subtitling have been caused by an admin/owner 
wrongly configuring the workflow / tasks settings). Combined with the 
possibility to add to teams existing, already already subtitled video 
subtitling pages created in Amara by others, there is a definite risk 
that a not-so-knowledgeable admin / owner might use that Delete Subtitle
 Language function to delete subtitles that were made before a video 
subtitling page was added to a team. (...)] 
 
So again: Amara staff, please withdraw this Delete Subtitle Language 
function, and rework it so that only the sole author of the subtitles 
affected can delete them.  
Unless you do, I'll have to suggest to all members of the Captions Requested and Music Captioning teams to remove the videos they have added to the team, lest existing subtitles get deleted by mistake or whimsy by a team admin/owner. In fact, in each of these teams, there is an admin or owner with that capacity whom it's impossible to know anything about and who never answers messages concerning the teams: in Music Captioning, 
fernandotakai (admin) and in Captions Requested, 
nuncho (owner). So far they have only played possum in these teams, but the idea that they might suddenly decide to use this Delete Subtitle Language 
function is seriously worrying.
And if you have questions or comments about this, please don't write them in a reply here but in a comment to 
http://support.amara.org/support/discussions/topics/25223/ on the Amara help forum: that's where issues potentially affecting all Amara users must be discussed.