Well, since I am assuming that "this thread" is partially directed at me, I will bite.

1. T who forgets clients information appointment after appointment after appointment

2. T who arrives late continuousally

3. T who utilizes the client for their own needs or wants and this could range from too much self-disclosure where it "hurts" the client to a sexual relationship to writing a book about the client without the approval

4. T who is untrained to deal with a client, but keeps them anyway and potentially does more damage; this probably comes into play with more difficult diagnosis or specialized issues like substance abuse

5. T who allows their countertransference to get out of control without seeking appropriate supervision; thus impacting the client's therapy

6. T who lies

7. T who abandons a client with no additional references or guidance

Now a T that is a JOB:

8. All the above

9. T's that do not consider sliding scale options when a long-term client is in financial difficulty for a "period of time."

10. T's that move long-term clients out of their regular time-period, to accomodate newer clients; without speaking with the long-term client first and working through it

11. T's that are not connected to the process and are thinking about their dinner plans during your session; or something like that

That's all I got at the moment. I am sure someone will attack me for my responses to your question and I will respond.