How to lock files on an external hard drive? (Mac)

I'm sure there are some tech savvy people here so I'll give my question a shot.

We're going to have a mac and external drive set up in a public space for people to view the material on it for research purposes. The tricky thing is, while we want people to be able to see the data on the drive, we don't want them to copy the material onto another external drive and take it.

Changing the read/write permissions to 'read only' keeps people from deleting the files (which is nice) but they can still copy files off the drive.

Anyway I can prevent people from copying files onto another drive? I'm starting to think the only way to do this is to glue the usb/thunderbolt ports shut....

Thanks!

Sounds more of a question for the PC & Mac Forums! You'll have more luck finding your answer there.

Sorry I don't have an answer for you, hope you find your solution! :)