As part of our efforts to improve BLAST+, we have implemented usage
reporting to collect limited data. This information shows us whether
BLAST+ is being used by the community, and therefore is worth being
maintained and developed by NCBI.
It also allows us to focus our development efforts on the most used
aspects of BLAST+.

See https://www.ncbi.nlm.nih.gov/books/NBK569851/
for what data we collect and how to opt out of usage reporting.