For me copyright is very important. Especially for the individual creator and his/her work, but equally so for company´s.
The Beatles / Apple Corps vs. Apple Computers is a tricky issue. Something that they faught over, the right to their logo. When a Swedish Enterprise in Dalarna (equivalent to State/county) wanted to use an apple as their logo, they chosed to create an apple, looking very similar to the Apple Computers apple. At the same time Apple Computers apple is looking a bit like The Beatles / Apple Corps apple. Now, many may think that this is a non-issue, especially if they believe that copyright should be abolished, dismantled and not let anyone own a copyright at all.
Well for me, it is rather a question of how, in this case, the apple looks like, How similar in design it is. Not that it is an apple in itself. Now, the apple by the Swedish Dalarna Company, if the apple they made had been approved by the PRV (Swedish Patent & Registration Office) , which it was not, could have been seen as different with its hand drawned style. But equally the problem of recognition and brand similarity would quickly occur, on the day the Swedish Dalarna company would be "updating" its logo with a re-design. This would probably quickly become very similar to Apple Computers apple. Furthermore, it would undoubtedly have been stopped because of the likeness to the Beatles apple.
Another example is the software company that develops the desktop publishing software "Quark". When Quark made a redesign of their logo, which they did for the release of its new Quark version, it was instantly criticized for its similarity to other logotyps. It was then redesigned again, but then it became in my view very similar to Sony Ericsson mobile phones logo. Does it sound chaotic? Exactly. Quarks sign is a story in itself.
But still it is important that a logo as much as possible is the logo of one company, not several, otherwise the similarity can be a problem. Why you may ask?
Well every year in Sweden bogus invoices keep pooring into legit companys. They try to fool economic departments during vacation time, when there might be temporary workers in charge of handling the payment of invoices. And the rest of the year bogus companys use similar logotypes and letter heads of legit companys, and send to private households and companys in hope that people will pay without looking and checking the invoices. Basically stealing their money.
So yes, logotypes and the "sender" being the correct one is extremely important.
Illustrator & artist