Links and Downloads Manager has implemented an option to restrict the number of times a user can download an attachment. Actually, it was I who requested the developer to include that option. See my exchange with AndrewD:
https://vborg.vbsupport.ru/showthrea...wu5#post924597
By the way, AndrewD is a very nice guy. He even PM-ed me when he first implemented that option:
"The new version of LD, 2.1.6,..., includes an optional extra to allow you to limit the number of times a document can be downloaded by a given user.
This is provided as an optional 'plugin' in the extras/limit_useraccess subdiretory of the zip. You'll need to read the instructions in that directory - it's not installed by default." (That was back in March. It might now include more options.)
I haven't got the time to try that option just yet. I don't know if it could also block repeat downloads by IP address. But I'm sure you can do it by user account.