Found this to be insightful as to why the site has been blocked.
"Of the 1513 pages we tested on the site over the past 90 days, 4 page(s) resulted in malicious software being downloaded and installed without user consent."
Rasmus Lerdorf – the creator of PHP – is currently trying to get Google to stop blocking the whole php.net website after it was suspected of containing malware. In a tweet earlier this morning, Rasmus posted a screenshot and suggested that the block was caused by a false positive.