>>/11277/
I did 2 tests on the following (not 3):

/ipfs/QmWS3GSCjzcvoKaNcRVmfPQzdou3tVRQvNGvEf3CV3SNrk
./blocks/FA/CIQHQPXHXHP2QALCVG3SAZZ6O3A4FPRXAIGWVQ3DNJHNLYKFCFBFFAI.data
is "Seems like BitTorrent has better data verification."+\n
isn't "Seems like BitTorrent has better d4t4 verification."
note: next = https://www.youtube .com/watch?v=qrQ0zgEyeJs

/ipfs/QmVMq8TdzWC2XoKByvoGQqMqHEkbRikJrpukReYscmYwHu
./blocks/NZ/CIQGQTZLZUE2MX6BCFHEEXL7AUB4Q4LXH57IFVBK5XLCC52ZAFUPNZA.data
is "10 Dark Facts About MLP That Will Ruin Your Childhood - YouTube"+\n
isn't "10 Dark Facts About MLP That Will Ruin Your Childhood - JewTube"
note: text from Brave Search for "weird mlp" which also said "Weird mlp \n Based on the provided search results, here are some examples of weird and unconventional aspects of My Little Pony (MLP) fandom: \n SOF (Semen On Figurines) and C*m tributes: Some individuals have engaged in unusual activities involving pony figurines and semen, which has been discussed on online forums like Reddit’s r/mylittlepony."

Process: (1) add some text which probably isn't already in IPFS to a very small repo (2) look in blocks/ to see which DATA file that text corresponds to (3) add that CID to an online large repo, called "HPC" here (4) Simulate corruption of that .data file in the larger repo (5) provide that CID to the DHT multiple times while doing step six (6) in a different online IPFS node, call it "MPC" try to pin said "corrupted" CID.

Results: MPC was never able to pin HPC's bad data CIDs. It could only pin it when HPC fixed the data back to how it originally was. Time on first test: ???. Time on second test: couldn't pin bad data over 5 minutes of trying, and once it was fixed, it pinned it within 50 seconds.

Conclusion: IPFS seems to not have "internal checks" (use ZFS for that I guess), but it does have "external checks" on data validity. IPFS gateways (except IPFS Biforst gateway IIRC) don't detect simulated corruption. Validating/transferring data across the IPFS network directly will "never" result in incorrect data; like pinning someone's folder which you don't have at all: if all of their data is not corrupt or incorrect then you will successfully pin that previously remote data. (If it's incorrect, then nope, you'll only get like 99.9% of it.) Lack of internal checking = more focus on backups.