After posting a feedback in the Hall, I was blackmailed to following day by the CEO of this agency suggesting that I should remove the feedback by 10 am the next Saturday in order to avoid trouble.

This was clearly blackmailing.

I am sure that such agencies will not go far. They are apparently only interested in their public reputation but do not know that it is more important to be truly professional.

My suggestion:

1.) Double-check your evidence for the things you state in your feedback, in case he will take you to court for defamation.

2.) If your case is solid enough, add a comment describing how he threatened you.

3.) If you want to be on the safe side for 20-30 EUR, ask www.frag-einen-anwalt.de
     Maybe their lawyer will suggest to file a report (Anzeige erstatten), which would not cost you anything.
 

Thank you, Harry.

Just a detail, after I checked out their HFS record and their website: this is not a translation agency, but a "translation marketplace" - which is quite a different concept with different (legal and other) consequences.  And I see they ask for full payment in advance, so how can they justify their nonpayment as translators also have a possibility to correct their work?

I see some difference to the real concept of an online marketplace such as oDesk. On oDesk, you would really trade your services directly to a client; moreover, client and vendor would know each other - similar to eBay.

This company is acting more as an agency. I did not find the definition "marketplace" on the website, they just call themselve "translation service".

Still the "marketplace" would be no excuse to refuse to issue PODs or at least some form of contract.

However, please also view their Terms of Service.

Awful! Why didn't TC check the (uploaded or scanned) operating license of the outsourcers before they posted jobs?

Because of what the TC Home Page says (you can't miss it):

The company in question is a registered company in Germany. It is not the issue if they are registered or not. It is the business conduct. It does not have anything to do with TC administration.

 Ho!

Matthias, generally when entities threaten translators in this manner, the translator posts the fact that he has been threatened.  That way all of us will know that this is an agency (or portal or whatever) to stay away from.  If nobody wants to work for such characters, what then?  I find threats despicable, but above all, unprofessional conduct.

As has been suggested, check what you have posted, whether it is factual and accurate.

Maxi

I had already checked the report. It sounds quite shocking but it is true.