Miners capabilities limits

Miners choose which valid transactions to include and in what order, and they extend the chain. That is the entire scope of their power. Miners can: temporarily censor transactions from their own blocks, reorder within blocks, and (with a large hashrate share) attempt reorgs to double-spend their own recent payments. Miners cannot: spend coins without the owner's keys, create coins beyond the subsidy schedule, change consensus rules, or force nodes to accept an invalid block — nodes discard rule-breaking blocks no matter how much work they carry.

Nuance: "The miners control Bitcoin" fails on the validity/ordering distinction (see nodes-enforce-rules), but miner behavior does matter at the margins: sustained majority censorship is a real theoretical attack on usability, and miner signaling has played a coordination role in soft-fork deployment (signaling is a readiness measure, not a governance vote — non-signaled rules can still be enforced by nodes, as the UASF episode demonstrated).

Common misstatements:

• "Miners could vote to change the 21M cap or raise the subsidy." — Blocks violating the schedule are invalid to every node; miners producing them fork themselves onto a worthless chain.
• "A 51% attacker can steal everyone's coins." — Majority hashrate cannot forge signatures; it can only reorganize recent history involving its own transactions and censor.
• "Miner signaling is how Bitcoin votes on rules." — Signaling coordinates soft-fork readiness; rule adoption rests with node operators and the economy.