Re: eXch - instant exchange BTC / LN / XMR / LTC / ETH / ERC20
Its true that they (US + Netherlands) briefly took over Hansa market after AlphaBay was shut down - perhaps the most famous of all bitcoin/darknet "honeypots" - but they only used evidence gathered to prosecute vendors on the market who were already active..
I have seen this happen when it made rounds on the news that an IRS agent had posed a crypto vendor on the Localcryptos marketplace just to collect evidence from some guy they had been tracking down for some time. It was an interesting case. 