You can always just not answer your phone, but if a telemarketer calling you on your Blackberry sends you into a rage, you might want to look at Call Control. The app relies on the telemarketer database at everycall.us to screen out known spammers. The free version screens out the top 100 telemarketers; an $8 version uses the entire database and includes updates.
Guests Behaving Badly (GBB) is an Australia-only customer blacklist that hotels there can use to weed out potentially bad guests. From their FAQ:
Last week, a developer discovered that the iPhone has the capability to quietly connect to Apple’s servers to check an application blacklist, and then disable any installed apps that are on the list. The story was quickly defused by blogs, but today the Wall Street Journal says Steve Jobs has confirmed that there really is an application “kill switch.”
The ChargeBackBureau sells merchants a blacklist with names of customers who have done chargebacks. Merchants are supposed to be able to access its lists and deny transactions to customers if they see they’re chargeback-prone. When a consumer is put on the list, they get sent an email warning them they’re “going to have trouble purchasing goods or services on the Internet in the future.” ChargeBackBureua’s headquarters are conveniently located in Panama, which is convenient for its American clients, as such databases are illegal in the US. Chargebacks are an important tool for consumers to fight back against merchants who won’t give you what you paid for. Here’s how to do one. If a merchant won’t do business with you because you stood up for your rights before, then you shouldn’t do business with them either.