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I am receiving large amounts of newsletter subscription signups which are coming in at a rate that is too fast to be real. When I looked up the ips from my online customers, some of the ips are proxy ips and other ips from Russia, Ukraine and France. I disabled newsletter signup and blocked a whole lot of ips, and when I enable it again, I was fine for a day or two and it started up again. Are these hackers or bots? Does anyone know how I could stop this?