: Massive networks of automated Google accounts created using rented phone numbers and proxy rotation to evade IP-based detection. Engagement Exchange Networks
Back in 2021 (and earlier), several black-hat websites and bots claimed to give YouTube subscribers for free. They worked by:
While "free YouTube subscriber bots" may seem like a shortcut to growth, they are highly discouraged due to severe risks and lack of actual benefit. Instead of using bots, there are and strategies that can achieve the same goal safely. The Risks of Using Subscriber Bots
This is the biggest risk. Using bots violates YouTube's Terms of Service regarding "Artificial Traffic." YouTube explicitly states that creators should not use automated systems to inflate views or subscribers.