Can IMPLICIT_TRANSACTIONS set on database level? When I have to investigate problems caused by IMPLICIT_TRANSACTIONS ON, can I focus on Client tools setting IMPLICIT_TRANSACTIONS ON or ANSI_DEFAULTS ON or can this be set for the whole database affecting all clients?

I can avoid the problem by changing my standard script header to

SET ANSI_DEFAULTS ON
SET IMPLICIT_TRANSACTIONS  OFF


but at which levels session, database, server can this setting be influenced?

Edit: 

I found this in msdn

it seems to be possible to set this on server level.

In the Server Properties dialog (Connections Page) I found the option changed and scripted it:

implicit transactions on:

EXEC sys.sp_configure N'user options', N'2'
GO
RECONFIGURE WITH OVERRIDE
GO


implicit transactions off:

EXEC sys.sp_configure N'user options', N'0'
GO
RECONFIGURE WITH OVERRIDE
GO


But executing

exec('dbcc useroptions')


in SSMS didn't reflect the change. The server setting seems to be somehow overwritten for such connections.

Now I have to repose the question, 

are there clients which do not overwrite the server setting and can crash when the server setting is changed.
Implicit transactions is a connection setting, it'll be set by the client tools and/or in the scripts only.