[ceejayoz]

Said gym memberships tend to be because you signed an annual contract, with specific requirements to cancel early.

Using one of these one-time-use cards won't get you out of the debt itself, and these sorts of gyms will happily wreck your credit by sending it to collections.

[Macha]

I've heard of some cases where the contract auto-renews and requires an in-person presence during a limited time window to cancel when they're quite busy.

While I'm sure these places have it in their terms, just making someone sign a contract to agree to it doesn't make it not-unethical or not worth criticising. It just makes it "not illegal in some jurisdictions"

[ceejayoz]

I certainly agree on the ethical front.

On the "use a privacy.com temporary card" front, the problem is functional, not ethical. They will sue you or send you to collections over the debt.