Yesterday I noticed in our apache logs that there is someone constantly accessing our website, sometimes 5 times a second or so, and sometimes once in 5 seconds. However, it's happening 24 hours a day. This has been going on for 5 days now and I think it's enough. The problem is that his IP seems to change almost every day. It's always in the following Chinese subnet:
112.94.*.*
As I do not want to block that huge range of IP addresses, what would be the best way to prevent this person from doing what he is doing?