Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Internet company Cogent Communications (Nasdaq: CCOI) fell 19% today after one of its customers was shut down by the Feds.

So what: was raided and shut down by the FBI in a crackdown of copyright infringement. According to the Department of Justice Megaupload leased about 36 servers from Cogent and paid the company about $1 million per month for its services.

Now what: Analysts say the company provided 2% to 3% of Cogent’s revenue and first quarter revenue could decline as a result of today's shut-down. Considering the relatively small slice of revenue the drop looks pretty extreme for Cogent's shares. I think they'll bounce back when we get more answers and see today as a nice buying opportunity.

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