Leech Computing is ‘a program running on a client computer without user knowledge that can process data and report back the results, but otherwise does not effect the usability of the client computer and makes no changes to the client’. This leech program runs only in memory, and does not access the client’s hard drive at all. In animal terms, the leech needs the animals, so it chooses large animals and only takes a little blood at a time without harming them. Can you spare a drop?