You do not have to get permission to quote someone or discuss their ideas, as long as you credit them. Just keep in mind, that you can't re-hash someone's entire article even with attribution, nor can you quote extensive portions of their work.

Copyright law is complex in some ways, and can be interpreted in odd ways if it should go to court, but in general, stick to never quoting more than 10% at most of any article or work. And fair use applies when you add in your own commentary, so simply restating their ideas is never enough to cover your butt.

Thank you Tina. No, I was not planning to re-hash, wanted to know the formality.

It is perfectly OK to quote short sections of their work, so long as you give credit. You can then add a reference number that goes to your bibliography, or you can go the whole hog and treat it as an academic reference (example below) but that depends on the type of writing that you are doing and your audience.


... Motoyama et al. (2010) make this exact point in their analysis of the economics of the CAPTCHA-solving ecosystem:

"[CAPTCHAs] ... exert friction on the underlying economic model and should be evaluated in terms of how efficiently they can undermine the attacker's profitability ... put simply, a CAPTCHA reduces an attacker's expected profit by the cost of solving the CAPTCHA. If the attacker's revenue cannot cover this cost, CAPTCHAs as a defense mechanism have succeeded ... CAPTCHAs naturally limit site access to those attackers whose business models are efficient enough to be profitable in spite of these costs and act as a drag on profit for all actors" (Motoyama et al., 2010, p.17).

then in bibliography/references:

Motoyama, M., Levchenko, K., Kanich, C., McCoy, D., Voelker, G.M. & Savage, S. (2010). Re: CAPTCHAs-Understanding CAPTCHA-Solving Services in an Economic Context. In Proceedings of the USENIX Security Symposium, Washington, D.C., August 2010.

Thank you, that's what I was thinking.

You have to reference your sources even if you are not quoting directly. If you are quoting large amounts of text, then you do need written permission.

Thank you.

Check the US Copyright code on 'Fair use' -it depends on how much you use and what the purpose of your usage is. Attribution is NOT ENOUGH to escape a copyright infringement lawsuit. Read the code and related cases. It's all about context.