They claimed "Monero can be traced", then fumbled when asked for proof

It seems to be they are simplifying the claim a lot, I believe technically it is true.

The only way to trace Monero is to link it to transactions in and out of Monero, which is only possible if someone doesn't allow enough time between purchase and sale, or sells the same/similar amounts of monero that they bought with the dirty coins, all at once. But I think we all knew this already.

@Kodomu yeah this. Timing analysis and coinswap metadata can be used to "trace" Monero. It is more difficult to achieve though because there is no transparent pool and because Monero utilizes many different coinswaps that are nonkyc.
There are known incidents where this has been achieved, but they are rare.

See: https://www.youtube.com/watch?v=ThbSLOVHKVE

@UsualCat
There are so many ways that you can leak data about your transaction to various parties. Even if monero does its job perfectly, you can still get traced if certain information is gathered. Think of it like assembling the triforce from legend of zelda... instead of power, wisdom and courage, they need your ip, the wallet that bought the monero, and where you spent it. Obviously the dealer knows where you spent monero. Obviously the liquidity provider knows what wallet you used to buy it, and probably your ip through tracing that. So if those two parties can get together and cooperate then most users are
DEAD EASY TO TRACE, no doubt.
That being said, Monero clearly works.

@Nebuchadnezzar_II how they know the ip? i so confused, any good reference that i can read? (other than compromised node)

@xenu and its easy for large transaction, but they struggle if the opsec was in place like splitting the transaction to smaller ones right? i mean its already hard to genuinely track single transaction over monero, so thats why the twitter things said they need to track it outside the monero itself
but when basic opsec in place, splitting and moving money in different ways including swap them, then i doubt any tracking wont be possible anymore. right?

@Kodomu hmmm i had other "opinion" about it
how about we booth had 1000$ transaction

differ was i was the bad guym and you're good guy. how to track each other? no one know i using bitcoinvn
or binance or what account i using right?

or no people also know if i swap it first
or just split the money to different wallet like 50$ each in BTC

@UsualCat There are a lot of ways someone can screw up. Coinswap sites harvest metadata and frequently respond to inquires by law enforcement, where they share things like IP address, transaction information, user agent, etc. Or perhaps the person incorrectly uses a transparent crypto wallet address that has associations with a doxxed kyc wallet address in the future. Or timing analysis. All it takes is one tiny fuck up (like being lazy and using a wallet address associated to a kyc exchange) to unravel things.
Attacking Monero strictly on the block chain is a waste of time for the most part.There are many examples of blockchain tx graphs showing btc moving to different addresses and dying at XMR. This changed the metagame and chain analysis primarily relies on kyc data and coinswap data these days. It is why there have been Monero frozen during coin swaps...likely the transaction was large or the individual was flagged for a suspicious inflow or ip.
Fortunately, and ironically, the frequent delistings have been enormously sucessful in making Monero harder to trace and to incentivize the creation of non kyc options. This is a uniquely Monero/Bitcoin community thing, which is derived from frequent legit usage of p2p cash away from cex data aggregation.
All of this is a case by case basis. How large is the tx? What is your threat level? Are you swapping into BTC? Into USDT? What websites or services are you using? Etc
Lastly - the importance of actual decentralized swaps is everything happens on chain, so things can't be frozen, but even in these cases public metadata can be seen (e.g. eigenwallet show tx_extra data in Monero and correlating extra info in the BTC tx that timing analysis will pick up). Is this the end of the world? Not at all, but if somebody was selling large amounts of XMR for BTC on a doxxed BTC wallet, and later sold at a KYC exchange, advanced chain analysis would probably be able to figure out you were selling XMR for BTC and ask you where those BTC transactions are from, knowing that you need to pay taxes.This is highly unlikely at lower levels but if you are cashing out millions you will be asked where you got the BTC from, and it would hypothetically be possible to connect the dots.

@xenu i mean in short its still "no way to get tracked" right?

like.. lets say i "doing something" then get away with 5K$ in monero
if lets say.... i swap it, split it, and exchange it
in "REAL WORLD CASE" no one will see it right?
i mean look

we had almost unlimited amount of CEX, DEX, etc.
no one can "guess" which CEX or DEX i use right? i think using monero almost guarantee "broke" any chain people had on it. example btc "tainted" then swapped to monero, then swapped to another like LTC, BTC, or even the Monero itself then become fiat. on my brain still, i dont see where people can get tracked.

and yeah for the last point, i indeed agree, if we cashing out huge amount of BTC, ppl will ask or prevent us to do that on first place, they will ask where we get that from, but for country which they had "presumption of innocence" in place, IRL will surely rare, people will allowed until they not. maybe on country who follow "reverse onus" which not that many on the world. its wild if people ask "does your money legit?" then ask proof from it and left us the burden to prove it. but yeah still somehow thats why i bringing the "argument" of split the money, so its not too much for the exchanger to handle, if its too huge. they will be.... THIS GUY SUS

@UsualCat
My reference is what @xenu just said.

The IP could be easy to find because you might have used a clearnet swap service, or node to buy monero.
But you're right this can be avoided with good opsec.

But a lot of users probably don't really care, because of a perceived or genuine sense of security. They just wanna buy something from dnm. I'm just saying that its dead easy to spy on these guys if the right data is matched up (like the triforce)

And the key point is that it falls on users to protect their own financial data, and without the perception of threat, most people won't bother.