Sybil is a cyber attack where an entity uses multiple identities either manually or automatically using bots. Why would someone use multiple addresses? Because each address is different. The eligibility algorithm checks your on-chain activities, not whether they were performed by the same person. However, protocols are now using detection techniques to find these types of attacks and filter out those who use hundreds/thousands of addresses. If you are eligible with 15 addresses, you get airdrops on 15 addresses.
The sybil cluster that is considered is at least 10 addresses. If you exceed this number also using bots for automatic interactions you officially become a sybil and are at risk of detection. There are some companies, including Nansen and Chaos Labs that are hired by protocols to find users who farm airdrops with multi-addresses.

If you use multiple addresses there are mistakes that you absolutely must not make to be eligible for any airdrops. A user could have multiple addresses also to try minting NFT from collections that they do not trust or new platforms. It is perfectly legal to have multiple addresses (up to a maximum of 10, then you become sybil). However, you could make serious mistakes.

1) Do not use the same address to "recharge" multiple addresses

2) Do not continuously send funds between your addresses

3) Use different exchanges or generate new receiving addresses for deposit

4) Do not use the same exchange to withdraw to multiple addresses. If you do this with few addresses (legit) avoid at least withdrawing the same amounts at the same time

5) If you are farming the same chains and dapps with multiple addresses avoid doing the same operations at the same time (same dapps, same amounts, same tokens)

6) Avoid Lending/Staking/LP of a few dollars, continuous swaps of a few dollars and mints of hundreds of NFT (you could be mistaken for a bot!)

7) If you use a dex (AMM) but also a bridge... avoid doing many swaps/bridges in a short time. It makes no sense to bridge $500 from Optimism to Polygon and as soon as they arrive bridge on Linea, then on ZkSync or do Arbitrum --> BNB Chain and after 2 minutes BNB Chain --> Arbitrum. It is inorganic traffic that may not be counted!

I fried your brain enough today, don't miss the next episode!

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