You'll note he used the word 'allegations', not proven facts.

Are you asking for evidence that the law was broken, or are you asking for the evidence that leads to the allegations? There's a significant difference in standard between the two.

The allegations revolve around campaign finance. If this data was shared with the Trump campaign, it was a campaign contribution, which has real value, which is limited to $2700 iirc. The data on 50 million Americans is worth well more than $2700. It really depends on if that data was shared, and if it should have been shared.

There is also the question of whether foreigners were working on behalf of the campaign.

There are a number of allegations that should be explored. Do a search, and you'll find these reports fairly easily.