Deleted posts - posts gone from website but associated files still present on server

Hello,

I deleted posts as Super User, some of them from frontend, some of them from backend (then deleted trashed posts). So they should be gone forever - however the files are still on the server - i.e. the consecutive article folders are still in folder: images/easyblog_articles.

Is this only my case or is this default that the EB files are not deleted from server after post deletion?
This makes a mess in joomla directory on the server and of course impact the website backup size.

I would be grateful for info,

Thanks!