One way to solve this problem is to create a data license that allows data sharing for replication use only until some embargo date set by the researcher. This would allow external researchers to immediately replicate published results, but would prohibit them from unfairly benefiting from someone else's hard work.
This exists and has been used successfully in a number of large consortia, like the Cancer Genome Atlas. It essentially says that the data goes live immediately, but the researchers who generated the data have exclusive publishing rights for 6 months from that date. After that, it's fair game for anyone.
