There is no rule of thumb on how many plugins you should have on your site, but if you choose to add functionality to your site using plugins, you should closely monitor available updates.As said - hundreds of WordPress sites get hacked every day. Statistics say that 98% of hacking incidents happen because of outdated plugins and themes. We recommend using the auto-update feature on vulnerable plugins and installing a managed web application firewall that sends automatic virtual patches to your sites.If you have a lot of plugins you should strongly consider using WebARX to protect your sites.