Case law in the US is that a computer copying something into RAM is a "copy" under the copyright act, and can be copyright infringement (MAI v. Peak Computer), the issue is whether making that copy is fair use, or otherwise authorized. Joseph P. Liu's "Owning Digital Copies: Copyright Law and the Incidents of Copy Ownership" is a good overview of the issues. I don't believe the law has substantial changed since he wrote the article in 2001.
https://en.wikipedia.org/wiki/MAI_Systems_Corp._v._Peak_Comp....