To Buy or To Buy?

Don't you just hate it when companies use the "opt out" tactic for automatic subscription or membership renewal? In other words, they automatically charge you for another term of service unless you preemptively tell them in writing to stop? A close cousin to that tactic is one some software companies use to make it hard not to sign up for their software after you evaluate their demo version. Here's an example. I evaluated a demo version of MacScan on my computer recently and once the trial period was up their popup started popping up to remind me the trial period is up. The only option their popup gives me is to buy - there is no option to decline or to even close the popup. And the "close" button is disabled. To get rid of it I have to restart the computer.