I think what's actually happening is Sparkasse is calling customers and asking them if they meant to do the transfer. If you say 'yes' they will send it. If you say 'No, I was hacked' then they'll reverse it. Sparkasse is not stopping their customers from sending wires to any bitcoin exchange accounts (at least that's my impression).
The information we received from Anycoin Direct tells an entirely different story though.
Apparently, they don't call every impacted customer. Some transfers are just reversed without any communication or reason.
However, not all transfer are affected either, so I'm still in talks with Anycoin Direct & other exchanges to find out what is going on.....