A sputtering economy, implosions at financial institutions, or just plain bad management -- on any given day, investors can name a number of reasons to sell a stock. Yet while panic never benefits investors, it's good practice to play devil's advocate with our investments from time to time.

In Motley Fool CAPS, more than 120,000 members have weighed in on more than 5,400 stocks, sharing bullish and bearish opinions alike.

In the case of Canadian mobile email king Research In Motion (NASDAQ:RIMM), a total of 4,658 members have weighed in on its chances of success. I've already plucked out some of the bullish rationale backing Research In Motion today, so here are three counterpoints to consider, courtesy of CAPS:

1. Falling behind
In an intensified smartphone market, some investors are concerned about RIM's increased spending for new devices and its ability to bring products to market on time. Steve Jobs gleefully pointed out that Apple's (NASDAQ:AAPL) iPhone sales the past quarter were 6.9 million compared, to 6.1 million BlackBerry sales. Apple's and Google's (NASDAQ:GOOG) application stores are already live, while Research in Motion's own storefront won't be up and running until March 2009.

2. Changing market
Competition from the iPhone and smartphones from Nokia (NYSE:NOK) and Motorola (NASDAQ:MOT) is dropping prices and creating margin issues in RIM's space. The company once owned the market and brought in steady profits. Now it needs to work harder and spend more to win over consumers by competing on price, features, and fashion. Even Hewlett-Packard (NYSE:HPQ) is getting in the smartphone market.

3. The party's over
Research In Motion has brought huge returns to investors over the past decade, but like other huge companies such as Oracle (NASDAQ:ORCL), it's not very likely to reach 10-bagger status from this point forward. Believing its best days of growth behind it, some investors think it's best to move on to better opportunities in smaller companies.

Of course, Research In Motion has survived and thrived despite dozens of obstacles. But whether the company can continue to do so is a whole different question. That's why CAPS is such a great resource to augment your own analysis.

To see what the very best CAPS members are saying now about Research In Motion, just click on over to Motley Fool CAPS and have a look -- it's all free, and your opinion's welcome.

Further skeptical Foolishness:

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.