I am not believing that number. I guess instead of getting pictures next to huge piles of drugs and money they can just say "we found 20 million bitcoins on his computer".
Yup, it doesn't make sense for soooo many reasons:
1- Even if that amount were total revenue is still a lot for that marketplace nowadays
2- Much less if it is profit, as it should be in order to be stashed and sizeable
3- Even if it were (well, it isn't) it is VERY improbable that someone "owning" that amount would have not stopped and run long ago. Because, 1) if your dark market is so huge you know it will be taken down very soon 2) Being able to cash out that much is basically impossible if you can't prove a legit origin... so why risk trying to make more?
4- If all the previous is not enough.... He would have take precautions to split and secure his stash in different ways as to making basically impossible to seize it all, or even a major part of it. So... should be assume his holdings/profits were even higher that 100,000BTC?
Yeah, complete bullshit... I don't even think we are talking here about 10,000BTC seized.... but, at least, that would have been a somewhat reasonable figure. Most probably they sized almost NIL and that is just an "estimation" of what could be "inside" the seized equipment of the evil kingping.
If the profits were accumulated over several years then 100,000 BTC wouldn't really be a lot. Especially if they reinvested some of the proceeds into altcoins. Even at last year's $1000 per BTC the profits would "only" have to be 80~100 million. Go another year back and you're in the several dozen million range, which I don't think would be all that far fetched for a large scale drug operation. And turning 10m into 100m with altcoins over a span of one year wasn't really all that hard even with blind spray and pray "tactics", which could realistically result in $1 Billion worth of BTC today with 2-3 year operation.
Also, your point #4 assumes foresight on the guy's part. And based on how some of the darknet markets apparently got busted that would be quite a stretch. Apparently one market had the admin literally use his real fucking real email for both the market registration or newsletter (don't remember) and on public forums that had direct ties to his real identity.
People who go into ventures like drug dealing are not the sharpest spoons in the drawer. If they were, they would be making money without compromising their security (getting murdered and/or jailed) by producing something of value or playing the existing markets.