Sanitize for style attributes

[isguyra]

It's really confusing to decide whether sanitize will help avoid XSS in case when :attributes => %w( style ) 

on stackoverflow, people say that it is not safe, yet the examples they give such as

style="background-image: url(javascript:[code]);"

is being filtered out using sanitize and all that is left is style="" 

is there a way to get a definite answer if sanitize with style allow will protect against XSS or not?