If you are part of an online business that gains any traction, you will likely face legal issues that have never encountered before. It could be a situation where you are on the receiving end, or it could be a situation where you have to expend funds to protect your business or your brand.
Here is a situation where a company might be hitting a little too close to home by basing their logo on another well known logo. The company who is pushing the boundary a bit is in the social networking business and probably competes with Yahoo in a number of areas. Take a look at the logos below. You be the judge.
In my opinion, the spirit of the logo was definitely taken from the Yahoo logo. This could have been a subconscious choice by the designer, or a decision made without care. The fact that they compete in a number of areas makes this a touchy one that is likely to raise concern in the legal department at Yahoo.
If you are building a brand online, be unique. Copying a leader will likely generate some legal costs and a change in your logo in the near future. Not good for your brand identity.