This topic has been covered a few times before here on BHW when people report that their websites have recovered after being hit by Penguin 1 and 2. I had a website penalised by Penguin 1... I did build links to it and i used WP templates to promote my website and one of the templates got installed over 2,000 times so over time I got over 1 million links with the same anchor text, so it's needless to say that penguin 1 hit me hard (I don't understand why it's my fault that people liked my template and used it so I got so many links for something nice I did). So I removed the content and moved to a new domain which is slowly growing as the time goes by... a few days ago I noticed that my old domain is ranking in google and bing again even though it has no links and I have robot.txt blocking search engines (yeah, search engines still crawl websites and ignore robot.txt but they don't show descriptions). You think it's safe to use 301 redirect to my new website to collect all the link juice from the old website?