For everyone who is struggeling with the W-8BEN Form (especially as a German):

I just finished filling it out with some help of my lawyer.
So you have to fill in accordingly:

Everything should be filled out with -> UPPER CASE LETTERS <-
Remember that the US can't handle ß,ä,ö and ü. Use SS, AE, OE and UE instead.

Part I
1. First name Last name (Last name = family name)
2. Country (GERMANY)
3.1 Address. Use STR. instead of STREET/STRAẞE
3.2 City + , + Post ID. (EXAMPLETOWN , 12345)
3.3 Country
4. Stays empty
5. Stays empty
6. Tax ID (in German: Steuer Identifikationsnummer)
7. Claim number (put your claim number in that you recieved per e-mail)
8. Date of birth. Remember: The U.S. uses a different order! Its Month - Day - Year, so 20. of January 1990 would be 01-20-1990
Part II
9. I certify that the beneficial owner is a resident of -> GERMANY <- ...
10. Special rates and conditions.
     My lawyer told me what i should put in there. You can use that if you are from germany, but i guess it would be different for other nations.
     "The beneficial owner is claiming the provisions of Article and paragraph 4 - 1 of the treaty identified on line 9 above to claim a
     0% rate of withholding on (specify type of income): CLASS ACTION LAWSUIT, OTHER INCOME
     Explain the additional conditions in the Article and paragraph the beneficial owner m to be eligible for the rate of withholding:
     UNDER ARTICLE 4 OF THE U.S. / GERMANY INCOME TAX TREATY I AM LIABLE TO GERMAN INCOME TAX BASED ON MY DOMICILE;
     RESIDENCE AND CITIZENSHIP. UNDER SEC 894.20 I AM ENTITLED TO US INCOME TAX TREATY BENEFITS AS ALL MY INCOME IS 100%
     TAXABLE IN GERMANY.

At the bottom, sign with your name, below you also have to write your signature in big letters again.
On the right the date, again like 09-29-2017.

Then make a copy of your government ID, drivers license or passport.
Also include a copy of the Cryptsy Settlement Determination Notice which you got per e-mail.

Send these 3 things via certified mail with return receipt (German: Einschreiben) to the address stated in the Determination Notice.
That's it

Hope i could help someone, this lawyer cost me 120€ to fill this damn thing out correctly