Update: As of 8-Nov-2017, this has been fixed. Hundreds of people followed through here and notified Google of the issue. Thanks everyone!
Googling “Ethereum” shows a very large logo – albeit the wrong logo – in an attractive info box on the right hand side. If that bothers you, then let Google know. Just click “feedback” on the bottom right of the info box and then click the incorrect logo.
The logo appears to be that of BlockGeeks.com – nice advertising guys. 😉
Thanks to reddit user sotech101 for the head ups!