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It happens to the best brands. One minute, they’re adored by millions. The next, they’re like Blockbuster, Friendster or Lindsay Lohan — sans fans, in need of rehab and largely ridiculed.

Interestingly enough, the backlash that follows bad consumer–brand breakups bears a striking resemblance to the fallout from failed romantic relationships. There are dramatic confrontations in the form of customer complaints. There’s the requisite returning of gifts (a.k.a. refunds). And there’s badmouthing among friends, or anti-brand vitriol on blogs and online forums.

Criminal behavior that borders on stalking isn’t out of the question either. Allison Johnson, who looked into the aftermath of consumer divorces for a new Journal of Consumer Research study, says some of the respondents she surveyed online even admitted to vandalism, service-employee threats and theft. (More on Time.com: How Retail Therapy Works: Spending Money for Social Acceptance)

The people who lashed out the most, Johnson says, tended to see themselves reflected in the brands they once cherished and got the most hurt when the relationships ended as a result. “Those who felt that the brands were theirs had the most to lose essentially,” says Johnson, a business professor at University of Western Ontario. “They became those same brands’ biggest enemies.”

Why former fans turn on their brands, however, is the larger question that Johnson and fellow marketers Maggie Matear and Matt Thomson sought to answer in their study. To find out, the researchers asked more than 800 respondents to identify a brand they no longer subscribed to and to fill out an online survey concerning it. The participants graded statements involving their initial level of attachment to the brand (‘This brand connected with a part of me that really made me tick’), the cause of the brand breakup (‘The brand left me’), their anti-brand behavior (‘I intentionally broke or damaged something of theirs’) and their current relationship with the brand (‘This brand is my enemy’). (More on Time.com: 5 Ways to Spend Wisely During Holiday Shopping)

Take the case of a certain young actress. Lindsay Lohan’s fans, Johnson says, may have felt inspired and attached to her during her teen-queen days. But during her troubled twenties, they felt betrayed because she no longer behaved in a way that they could identify with, so they ended the relationship. They then felt so foolish for loving her in the first place that they felt the need to criticize her just to disassociate themselves from her.

It’s that feeling of being the fool that motivates some brands’ exes to turn mean. Johnson and her cohorts say self-conscious emotions like embarrassment and shame drive the most extreme retaliatory behavior. Though their actions suggest that they’re angry at their one-time brands for misbehaving, they’re really angry with themselves for ever believing in the brand. (More on Time.com: Retailing: No Embarrassed Customers)

“Shame is an extremely toxic emotion,” says Steve Kates, a brand expert at Simon Fraser University. “It makes people feel as if their entire self is worthless…and engage in very destructive actions directed toward the offending company.”

But the tricky thing for image and brand consultants is that, sometimes, there are no offending circumstances. Johnson’s survey respondents for the most part didn’t confess feelings of brand dissatisfaction or changes of heart resulting from what marketers refer to as critical incidents (i.e. celebrity scandals or company crises). They simply fell out of love with their brands. “It’s similar,” she explains, “to a personal relationship where you just wake up one day and go, ‘I don’t remember why I married you?’”

So how do brands win back their exes? They don’t, Johnson says, or at least they shouldn’t. For one thing, it may be too late once consumers have begun their anti-brand rampage. For another, reparations like discounts or special promos may be misconstrued as insincere attempts to win back business, making the perceived betrayal that much worse. Roland Rust, the marketing chair at the University of Maryland, adds that there is no sure way to prevent bitter breakups. “Parting with a brand,” he says, “can involve the stages of grieving that correspond to any significant loss.” (More on Time.com: Top 10 Badly Behaved Celebrities)

That is to say, when avid followers turn rabid, helping them move on may be the best way to appease them. Practically, Johnson suggests offering everything from an apology to an alternative brand, even if it’s a competitor, to restore a semblance of trust and their sense of self. “Helping them save face,” she says, “is essentially what it comes down to.”

Still, companies and personalities can only do so much. Forgiveness, or at least indifference, will have to come from consumers who perhaps shouldn’t even be taking things too seriously. “A brand doesn’t mean anything about you as a person,” Johnson says, adding, “It’s a commercial relationship.”

More on Time.com:

How Blockbuster Failed at Failing

Why Netflix Stinks: A Critic’s Complaint

Behind the Troubles at Toyota