Hosting data on public repositories is the norm these days, and this is beneficial to researchers who host their data, while at the same time making the data available for all. All datasets on public repositories like Figshare, Dryad, etc., are published under a CC0 license. CC0 reduces legal barriers to the reuse of data, but users have a responsibility of to cite the source, as is the norm in the scholarly community.
Additionally, the Figshare website mentions that all data will have a DOI and will be citable. The DOI will appear in citations, making it easier for other researchers to get back to the original data - in this case, your data. Thus, although users will not be required to ask you each time they use your data, they will need to cite it. That way, your study will receive more citations.
Moreover, as per the PLOS ONE guidelines, you will have to host only the “minimal dataset” on a public repository. The “minimal dataset” refers to the data that is pertinent to the study findings, that is, only the data that will be required to replicate the study and reproduce the results. Thus, you do not need to host all the data that you have collected in the course of your research on the repository.
However, if you have concerns about openly sharing data due to ethical reasons or to protect the privacy of patients, you can inform the editorial team. In such cases, they usually have policies that allow the publication of the paper maintaining the appropriate level of security.