For most crypto users (especially, the “not so careful” once), the cost of their privacy would usually cost the price of an airdrop they collect.
How so?
Well, let’s put it this way: when an airdrop is announced, most users will collect all utxo’s into one single tx and then share that key with the related airdrop address. By hence, basically revealing to both chains your tx history.
If by a chance, one of those addresses was also involved in a KYC procedure (say an exchange address), then it gets even easier for anyone to know who you are.
So, what is the cost of your privacy? Is it your identity? Can you do anything?
Well, for a starter, use different emails and IP addresses. Use mixers that cannot associate you and your ID. Don’t do the obvious (described above). Do not collect airdrops that aren’t worth it. Do not use addresses that have passed KYC \ AML procedures.
Saying that anyone who really wants to follow your tx logistics, will be pretty much able do, even you are careful, after an airdrop claim.