I feel a bit reluctant giving them much of my data just to match me with their potentially non-existent records and so allowing them initiating new records on m

I feel a bit reluctant giving them much of my data just to match me with their potentially non-existent records and so allowing them initiating new records on me covertly. Also no way checking if they lie about the dataset on me. I feel better not sharing data in general, anywhere, except when it is really essential. So many businesses lost me on potential or factual trade because before(!) answering my questions or giving very basic information (e.g. price!) on their services they wanted to collect lots of factual data on me. I said no, good bye!