pdfdrive.netは安全ですか？

This is not really a negative review but more an expression of concern. I landed at pdfdrive.net following a link from another site claiming I could secure a particular title on web site creation for free. I find, however, that registration is necessary, purportedly on a "free trial offer" after which payment is required (thus it's not free). That by itself seems reason for concern, but there's much more. The site seems to offer access to a lot of texts that are clearly protected by copyright. Whether the site is violating these copyrights or not I can't say for sure, but at best it looks quite fishy. ***** also uses several highly questionable tactics to push its products. The site "baits" the user offering interesting titles and "download" links, but when the user clicks on the link promising a download, the site "switches" the use over to a "free trial" registration page (thus classic bait and switch). Also highly disturbing: Every 60 seconds or so, the site sends a pop-up that has literally nothing other than the site's name. Yet the pop-up drags the user back to the browser tab with pdfdrive.net even if the user is on a different tab (as I now am, for example, on ***** trying to write a review of the site). The pop-up effectively "locks" the user onto the pdfdrive.net site until the user clicks either "OK" or the cancel "x" in the pop-up's upper right corner. Until the user takes such action, there's no escape from the pdfdrive.net page. The site effectively "locks" your mouse until you click through its no-content pop-up. All-in-all, the tactics this site uses reek of unethical manipulation. That said, I claim no depth of knowledge about what they're up to. A "whois" search reveals nothing useful. I'm not convinced that this site is ultimately "bad." But because its tactics are troubling. I hesitate to explore much further. Whether malware or viruses lurk in downloads, I can't say. Has anyone else had any experience with this site?