With nearly 23,000 subscribers, of which roughly 60 percent are residential customers, Doyle Security Systems Inc. Rochester, N.Y., is currently ranked No. 44 by recurring monthly revenue in the SDM 100. The company is one of those rarities of the security industry that have managed to remain family-owned and operated for nearly a century. Doyle Security Systems has done this while maintaining success, growth and a first-rate reputation — they’ve even been awarded by the Better Business Bureau.