When you download and install a software product you agree to its terms and conditions.
People generally tend to forget this, they just Next/Next/Next till the end of the installation.
They don’t really mind about what they’re signing when they’re selecting the “I agree” option.
There’s the common misconception that, once bought, you become owner of that particular product.
Well, actually, that’s not true. The End User License Agreement you usually find in proprietary software grant you the right to use that particular piece of software.
The GPL differs in this, because let you modify the code belonging to the Program as you like, as long as you release the changes under the same terms and conditions.
When you buy a forum script you usually are forced not to remove the copyright notice telling you’re using “Hell-Knows-Bulletin”.
You bought for that and you can’t even remove a copyright notice. Damn, no, that would mean infringing intellectual property!
With GPL’d software you don’t have this restriction. You have copyleft, where you had copyright.
This doesn’t mean there’s no more copyright, tough.
The work still belongs to his author.
By the way, technically speaking you can even remove the “Powered by” notice. And some people do.
The point is: is this ethical?
The answer is obviously NO. And with “no” I mean firm, big NO.
This is in my opinion totally unethical; the open source developer gives away his work for free, and all that he asks is credit. And I don’t mean you should pay for his work, just that you should be so kind to tell people that you’re using his platform, the fruit of his work.
He’s giving it away without asking back nothing more than some personal glory and the joy of having shared something.
Security through obscurity? Quite meaningless.
If you use Free Software, support it.
You can contribute with plugins, themes, patches, reporting bugs, giving your advice, translating, documenting, or if you are lazy, by doing a small donation.
If you really want to remove the “Powered by” notice in your open source piece of software of choice, consider at least doing a donation.