I wish BTC is not used for illegal activities though it is a currency. Legal and illegal activities require money. It depends on who uses the coins. Lets utilize the bitcoins only for good purposes as it was created to benefit all and lets bring more fame and name to bitcoins and its founders.
As long as bitcoins has value and can buy anything, then it will be utilized for illegal activities and other criminal-related stuff. Same goes to fiat. Also, as long as there would be ill-minded people, there would be illegal activities, and you cannot control those factors no matter how hard you try.
Thats right, anything that has a value can use in illegal activities.If bitcoin has no value anymore it will not be able to use it to illegal activities cause no one will accept trash.