[mikeyouse]

From Crunchbase:

Impermium is a cybersecurity technology startup that protects over 1.5M sites and has processed over 8B total transactions in its 3-year history. The company’s advanced risk-evaluation platform improves account management by identifying fraudulent registrations, compromised logins, and risky transactions. It has proven successful at stopping fraudulent user account registrations in real-time — using a blend of machine learning, statistical anomaly detection, and a proprietary database of malicious actors — for hundreds of transactions per second from many of the largest consumer Internet companies.

It looks like it was founded in 2010 by a few ex-Yahoo! spam guys and had raised $9mm in 2 rounds from the typical list of tech VCs. LinkedIn lists 20 employees, so probably 30ish total.