Hello! So there are different kinds of botnets. Not all botnets are bad and not all types of botnets are bad. The main idea of a botnet is this. There is a master, which is the middle of everything. Around it are little tiny computers latched onto it, these latched on computers tend to follow everything the master commands. Now although this is true for HTTP botnets like Zeus this is not true for a botnet which would be for example a QBOT. The master concept is still correct, but the computers are instead infected devices which have been exploit through vulnerabilities, for example the vulnerability in SSH or busy box routers allows simple servers to scan and brute force then allowing some of them to join, if the connection is not closed off by the server. Then there are IoT (Internet of Things) Botnets like the Reaper or the Mirai, which are specifically designed to allow anything connected to the internet to connect to them through them by executing Mirai malware. The Mirai over the past two years has made a name for its self because someone DDoSed at over 1 TBPS. Which is a crazy amount. If you would like to explore the Mirai source code and how it works then just googling "Mirai Source Code" would be your best bet. Conclusion- People who claim to have a botnet, probably won't infect you unless they have a HTTP botnet and send you the actual malware to infect you with. QBOTs and Mirai's will most likely be used to DDoS you if you are threatened by them, and all in all. Do not be afraid of someone that is threatening you with a "Botnet" because most people do not even know what a botnet looks like. Hope this helped you out a little bit man