Providing metadata is now sufficient to be infringing? If I SHA256 hash my entire media library and post it online, is that infringing?
How would you like if someone found your address and posted detailed instructions about how to get to your house, what hours of the day you're not there, and what type of security (if any at all) is installed? Maybe along with other "metadata", such as information about your neighbours, your job, your family members, etc. Enough to enable someone to perform social engineering on your neighbour or relatives to get them to open the door for them when you're not there.
Posting that could violate some other laws, maybe it could constitute harassment, depending on where you live - but it's not a violation of copyright, and if you would file a DMCA request to take that down you would be rightly declined.
You can post a lot of things on the internet that might be bad, illegal, or both - but only a narrow subset of that is a violation of copyright, and all the rest, including magnet data, private address information, stolen credit card data, etc are out of scope for DMCA.
There is some caselaw about what happens in that case (e.g. Grokster) but it's more complicated than "if you link to The Hollywood there is jail."
The commenter you're responding to is being slightly coy, yes, but they're not really wrong in that there is a difference between purpose and ability, both legally and in terms of plain common sense.
Thepiratebay can be used for piracy, and personally, there is little doubt in my mind that piracy is what many users go to the site for. However, the mechanisms by which TPB operates are by no means exclusive to piracy nor do they encourage it. That is, to the best of my knowledge, there is no payout for having a popular link on TPB. The TPB folk do not actively seek any specific type of content, nor to the best of anyone's knowledge do they have agreements with actual pirates to have said pirates release their content on TPB. Their website does not encourage users to download pirated content, nor does it intentionally direct them towards it. (Recent/Top100 links are algorithmically determined, not intentionally curated by TPB staff, so I posit this is not directing users towards pirated content, even if sometimes that is the end result)
Like the above poster wrote, TPB is a search engine that is restricted exclusively to their database (the tracker). To call such a broad idea "piracy" is really poor from any legal or common sense standpoint, as the very act of searching in this manner is not in and of itself a crime.
I understand that you're frustrated that the poster is refusing to outright say people use TPB primarily to pirate, but the entire basis of the argument for TPB is the same as virtually any other aggregate site; they are not purposefully or willfully collecting pirated content, and as long as they are DCMA compliant, which according to both easyDNS and TPB is true, I see no reason why they should be removed.
If the law changes and further defines the legality of what is and is not allowed on a website, then there will be at least legal grounds for removing TPB. As it stands, the legal attempts to remove TPB are very grand and sweeping, and outside of when they were ignoring takedown notices (which early on were from jurisdictions foreign to where the operators and servers were hosted), there is very little justification to "shut down the site" like the RIAA is requesting. These organizations have a legal venue, and it is the DCMA and all of its already over-reaching power. The fact that these organizations have to do their job is not a reason to further restrict content online, be it in the name of stopping piracy or not.
Half the inventions of modern society wouldn't be legal if the criteria were instead "can be used for illegal purposes."
An infohash is not exactly revealing metadata. Similar to publishing just your name and nothing else.
Of course, it's still a pretty crazy stretch because a name reveals even more than the infohash does.
Never forget the list.
All what you mention I can find legally in free databases and Facebook, not to mention legal but pay-to-access sites too, or simply firing a PI.
Just give me your full name and age (I don't need exact DOB) and bitcoin me 20 bucks for a few paid sites and I will delivery you a full detailed portfolio on your persona that will be 50 pages thick.