I am researching negative SEO to get an up-to-date view of this activity and I?m interested to hear of peoples experiences. Personally I don?t condone this type of thing and recognise that it is of dubious value, often illegal and is more likely to waste time and reflect negatively on the instigator than cause any issues for the targeted competitor site. But maybe you have a different point of view and some real experiences to share?. Here are some of the tactics that I have heard of : 1) Google bowling. Pointing a high volume of links at a competitor site in short period of time. 2) 301 Redirects from a Google banned site. 3) Dropping links in blog comments and then 301 redirecting to bad neighbourhoods / sources of malware. 4) Duplicating content from RSS feeds to a domain that?s older than the source in an attempt to be attributed as the origin. 5) Submitting fake reviews or agreeing with or promoting pre-existing negative reviews. 6) Establishing a volume of online content in minisites, blogs, web 2.0 sites etc. that denigrates the competitor, their products or services. 7) Posing as someone working for competitor and approaching SE?s with link purchase requests. 8) Screwing up a competitors analytics data causing their SEOs to investigate non-existent issues or modify their marketing campaigns. 9) Backlink hijacking by duplicating a competitors site then approaching their link sources and getting their link targets changed to the new URL, then 301 redirecting to where you want. 10) Using DDOS to adversely impact a competitor sites ability to support transactions. 11) Hacking into competitor sites (and others) and dropping cross domain canonicals to redirect and steal link equity. 12) Click fraud - Building up a natural looking high volume of PPC advertisement clicks to eat a competitors advertising budget. 13) Trashing competitors? reputations on social sites and forums. 14) Submitting fake email spam reports.