I believe this is correct, in fact, there was a newsletter service about a year or two ago that advertised to be doing exactly this – scanning the web for news on stocks that would move a particular, usually small cap, stock and then immediately recommending buying (or selling) the stock to subscribers via email. Don’t know what became of the service. – Ilene 
Newsbot Hair-Trigger
Courtesy of Cassandra Does Tokyo.
Whether you knew it or not (or believed it), some shops have strategies that are based upon bots that scour the web for market-moving events and significant news changes, and trades accordingly. Not passing judgments here, it is sufficient to say such pursuits are still in their early days, with some of the ummm errrr kinks yet to be worked out. 
At least that is what can be inferred from the erroneous plunge in the shares of United Airlines (UAL) as recounted on Hardware News on Wednesday (hat-tip to NT for the link).
Yes, an obscure almost irrelevant mis-classification of known and stale info triggered sales that crashed the shares. While the bot-based strategy was deemed to be the initiating source, it was NOT the entire reason for the rout. Indeed, a cascade followed, presumably fed by stops, position initiation by trend-following and order sniffers, that caused sufficient moves to panic and trigger real investors to short-sell or puke existing positions, and/or limit automatic liquidity-providers uptake – at least until "the news is out". The situation wasn’t helped by the company’s teetering-on-edge financial position and near-serial use of chapter-11 protection.
Boys with toys indeed!!
