Yes, but they clearly state - "To register your payment information, we will ask your bank for a 20,00€ debit preauthorization. This will appear on your bank statement and be automatically released after 7 days.".
This is a fairly common practice to weed out stolen credit-cards and to make sure you are real subscriber/customer, no biggie.
20 eur is quite uncommon, it's usually 1 or 2 usd/eur. So I skipped reading these two lines of unassuming gray text and entered details of my disposable visa with like 5 usd on it.
Except when you add a credit card, they try to bill you for 20EUR right away.