SEO Intrigue and "black hat tactics"

I tell potential clients all the time to be careful with who they use for SEO. Companies that incorporate "black hat tactics" will boost your ranking for a short time but Google will usually find the violation and take corrective action.
Don't think it can happen to you? Think again. BMW Germany and most recently JC Penney have both felt the wrath of Google due to violations. Check out the article (click on the title of this post) on The NY Times website regarding the tactics employed by JC Penney's optimization company.
JC Penney's "boosted organic results" were short lived but did take place during Holiday shopping season so it was good timing but now the company's site is all but invisible on Google. I especially liked the example used in the article regarding Samsonite. JC Penney was in the first organic position on Google for the search 'Samsonite carry on luggage' ahead of SAMSONITE. Questionable SEO tactics may result in short lived gain but now JC Penney is in 78th position for the same search.
Again, be careful who you use to optimize your website. A well-known, reputable company is such for a reason.