As a general rule of thumb slideshows and moving content should be avoided as it is not fully accessible to keyboard only users and screen reader users.

Users with disabilities should be given adequate time to interact with web content and should be provided with the ability to pause, stop and hide any moving content.

Slideshows and moving content that cannot be stopped and paused by keyboard only and screen reader users must be disabled. 

Having something repeatedly moving across the screen is very distracting, especially for users with learning disabilities.

Any slideshow related content should not contain anything that flashes more than three times in any one second period, or the flash is below the general flash and red flash thresholds.