Anything that can hold/represent Fiat value can be used for illegal activities.
If you are still trying to mine bitcoin today, most probably you are spending more money than the worth of bitcoin you get (after electricity and depreciation cost of H/W). Bitcoin mining is now an industrial level game.
The technology behind Bitcoin, the BlockChain, is currently being looked at by many banks and stock exchange. Heard of Ethereum (ETH) that built a platform to empower people to develop Smart Contracts (DAPPs - distributed apps)? ETH was damp profitable to mine with GPUs from Jan to early Mar this year (2.5x to 3x the cost). It was also profitable earlier but the wallet was just too technical to set up and difficult to use the miner. It is still very profitable to mine today and is easy to start mining.
If your cost is $100 and generate $80 worth of Bitcoin for donation, mining ETH with $100 cost should generate $200 worth of ETH for donation.
Mining should be a hobby as new technologies/solutions are being introduced regularly. You have to be able to spend time to keep up to date. Now ETH is profitable and more and more people are mining it. The day will come pretty soon when ETH is no longer profitable to mine and you will have to find new profitable Coin(s) to mine.
If you want to start mining hobby, visit
http://cryptomining-blog.com/ for a start.