i’ve developed an intranet application and implemented an custom ASP.NET Membership Provider with Forms-Authentication. I thought it would be a good idea to log all failed login attempts in DBMS. Hence i’ve created a table with following model:

Now my question:
Is it good practise to store this for safety reasons or is it even forbidden due to data protection reasons(germany)? I’m storing the original passwords hashed in db but the wrong passwords(or correct pw with wrong username) in the log-table are in clear-text.
Somebody could argue that everybody with access to this table could get user’s passwords not alone for this application but for others too, because people who have forgotten their passwords (or their username) might try out others as well.
Not a good idea for users who misspell their user ID but give the correct password!