I have recently decided to use an overlay that users can choose to pick the country of their choice. The overlay was originally going to be a little bigger than the average pop up & cover part of our content. It would only appear the first time the user appeared on the site. The designer i am working with is proposing to use an overlay to cover the entire content - forcing users to pick a country. The size would be 900x1200px I worry that this could have an effect on SEO & may be considered a cloaking technique. Can anyone comment on this? Is it risky to cover the entire screen with the overlay? Does size make a difference?