Comments and pictures parents post on Facebook can come back to haunt them during custody battles, debt-collection efforts and job applications.

A compromising Facebook post “is like a smoking gun in that you can’t destroy it,” said attorney Shawn Kenney, the law department team leader at Thrush Law Group.

Kenney said he’s seen custody cases hinge on arguments of parental incompetence stemming from Facebook posts. He recalled a case in which a father posted a picture of himself proudly displaying a 3-foot acrylic bong. In another case, Kenney said a mother wrote about how she’d been out with her girlfriends “getting trashed for the third time this week.”

“When people put information on Facebook it may not be in their best interest and does come back to haunt them in ongoing litigation involving custody,” Kenney said, adding he’s also seen a mother call her young boy “my pimp” and a father post a picture of himself baring tattoos while posed with a butcher knife, joking that he was a killer.

Divorce attorney Robbie Lewis, who owns the Law Offices of Robert G. Lewis, P.C., has also seen Facebook rear its often-ugly head in custody battles.

“The whole face of discovery in divorce has really changed over the last few years,” Lewis said. “I can’t tell you how many times clients have found out about extramarital affairs through looking through their spouses’ telephones in the middle of the night, or checking their spouses’ e-mail or Facebook accounts.”

Lewis said in the past, clients would hire private investigators to dig up dirt on spouses. Now the evidence can be found with a few mouse clicks.

“People put silly things on Facebook accounts – pictures of themselves or other people in bars doing inappropriate things” that end up presented at trial, Lewis said.

Attorney Grady Wade, who, along with his work in other legal fields, defends clients in debt collection cases and sometimes collects debt for creditors, said while he doesn’t personally use Facebook to investigate debtors, anything people post publicly on Facebook is fair game.

“If they put stuff up there, it’s pretty much for public use,” Wade said. “If they don’t make the page private, then it’s for public use and they don’t have any expectation of privacy.”

The Fair Debt Collection Practices Act, which prohibits abusive behavior and restricts the methods collectors can use to locate debtors, doesn’t prohibit using social networking sites.

Wade said third-party debt collectors aren’t allowed to publicly shame debtors. For instance, a collector couldn’t become a friend of a debtor under a false pretense and then post something on his wall about him owing money.

The restrictions don’t apply to the creditors themselves, Wade said, adding that he’d advise clients to record any contact with a third-party collector.

Tucsonans applying for jobs at the University of Arizona, the region’s second-largest employer, had best clean up their Facebook profiles.

UA human-resources manager Chris Wolf said managers dig up whatever information they can to vet job prospects, and Facebook is within limits.

“If a candidate regularly references violent behavior, then that may be a red flag,” Wolf said. “It’s more likely that a hiring manager will discover that someone references topics such as their political views – irrelevant when it comes to determining whether they can perform well, yet it may create an unintended bias.”

No matter the context, Kenney said people should stop thinking of Facebook posts as semi-private announcements to close friends. He recalls a mentor’s advice from decades ago, advising him to be careful about what he put in writing and says it applies to social networking sites:

“Never put anything on there you wouldn’t want on a billboard on the highway,” he said