Piracy: ꜱᴀɪʟ ᴛʜᴇ ʜɪɢʜ ꜱᴇᴀꜱ

A DDL (direct download) implies you are downloading it from a hosting site and storing it on your personal computer. A DMCA notice is sent when you are hosting the file and providing it to others.

Per https://www.legalzoom.com/articles/i-got-a-dmca-notice-now-what

"Copyright infringement has become so prevalent that sometimes you are not even aware that you are infringing on another person's rights. Most of the time, copyright infringement is an innocent mistake—such as reposting an image on Instagram that you like and want to share. Other times, the infringement is intentional. Either way, if you infringe on someone else's copyright, you will very likely receive a Digital Millennium Copyright Act (DMCA) takedown notice."

Further down the site

"Your next steps

Once you receive a DMCA notice—either directly or through your ISP—review and confirm the alleged copyright infringement listed on the takedown notice. If you can confirm that there is a copyright infringement, you should proceed with taking down the identified material."

This is the same reason you aren't at risk to DMCA when using Usenet/IRC because other people are providing you the files or downloading (not uploading) from google drive shared files.

If you use torrenting (which implies you are seeding back to other people) or upload to google drive you can be at risk to receiving a DMCA takedown notice and then you'll have to decide whether to fight it or delete it.

Because the studio would have to set up a honey pot site, host the files and get you to click on it. It's so much easier to just sit in the swarm and spam letters to everyone else.