Web Scraping detection and referrers

Here's the Irule i put together incase anyone else would need a sample or have any suggestions on improving it. I am checking the Method and the content length twice but I wasn't sure if that HTTP_Request_data event could/would get fired off by something else. It appears to be working for us so far.

 when HTTP_REQUEST {if { [HTTP::method] eq "POST"} { Trigger collection for up to 1MB of dataif { [HTTP::header "Content-Length"] ne "" && [HTTP::header "Content-Length"] <= 1048576} {  set content_length [HTTP::header "Content-Length"]} else {set content_length 1048576} Check if $content_length is not set to 0if { $content_length > 0} {  HTTP::collect $content_length}}}when HTTP_REQUEST_DATA {if { [string tolower [HTTP::method]] eq "post" } {        if { [HTTP::header exists "Content-Length"] } {log local0.info [HTTP::payload]foreach p [split [HTTP::payload] &] {set name  [getfield $p = 1]if { $name ends_with "_rf" } {set value [getfield $p = 2]set value [URI::decode [getfield $p = 2]]log local0.info $namelog local0.info "Retaining Referrer: $value" HTTP::header replace Referer $value}}}    }}