“Something for nothing” sounds appealing, but often there’s a hidden cost. If the something is a site or app offering free downloads or streams of well-known movies, popular TV shows, big-league sports, and absorbing games, the hidden cost is probably malware. Sites offering free content often hide malware that can bombard you with ads, take over your computer, or steal your personal information.

We recently downloaded movies from five sites that offered them for free. In all five cases, we ended up with malware on our computer. Generally, it served up a slew of unwanted ads.

And if that’s not enough to make you pause, downloading pirated content is illegal.

Finally, some free download sites ask for a credit card to process your registration. It’s not a good idea to give your credit card number to a site offering illegally downloaded content. They’re run by “pirates,” not legit businesspeople, and you can’t trust them with your financial information.