I must admit i'm not too sure about the legal aspect of it. The Google terms of use seem geared towards stopping people using it for commercial gain.
However its states: 'You may not copy, reverse engineer, decompile, disassemble, translate, modify or make derivative works of the imagery, in whole or in part. You also may not rent, disclose, publish, sell, assign, lease, sublicense, market, or transfer the imagery or any part thereof or use it in any manner not expressly authorized by this agreement.'
So who knows? Anybody better at the small print? The Google terms of use can be found
Here.