Just because you can find it online, doesn’t mean it’s free! Protect your business by having the right permissions for use of content on your website. If you create it yourself, you have less problems.
Software for the internet is so sophisticated and quick today that it is easy to find copied content. Companies that in the business of selling copyright, like Getty’s Images, automate their whole system so that they find the image you are using without permission, send you a letter demanding payment of a licence fee and follow up without necessarily needing human interaction.