What are "tagged" Bitcoins?
Source: https://www.theguardian.com/technology/2013/dec/09/recovering-stolen-bitcoin-sheep-marketplace-trading-digital-currency-money
I think it just means that some users discovered this address: 1Eg8WSxvfeZaKmqhNZrECTUb58x3y1AWYN and maybe few others involved in their past transactions to the darknet market. They tried to send small amounts to these addresses hoping they could track when its moved.