Over the weekend Google has flagged two very popular sites as malicious. Delicious and most recently Bitly.

Bitly has now been removed from the malware list, but Delicious is still listed and if you do a site search in Google you'll see that Google is being quite aggressive about flagging the site.

Wordfence recommends that you do a full Wordfence scan on your site. It may not be feasible to remove all links to Delicious, but if you have any pages that are critical to your SEO strategy and rely on a high search engine ranking, remove any links to Delicious that are on those pages. This will ensure that if Delicious remains listed as malicious then your search ranking won't be harmed.

A more in-depth report about Google's comments regarding the flagged sites can be read here