One of the frustrations faced by family members is how hard it can be to protect a grandparent or elderly parent who's vulnerable. Sometimes the victim doesn't want to admit a need for help or is afraid of physical or emotional violence from the predator if he or she complains, said New York attorney Michael Amoruso, who serves on the board of the National Association of Elder Law Attorneys.

"I see too many seniors who are terrified," Amoruso said. "They need to know that no matter how helpless they feel, they have the power to change things."

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Anyone who wants to report abuse or who suspects a senior is being abused can call the Eldercare Locator at 1-800-677-1116 and ask for help, or contact the adult protective services office in the county where the senior lives.

Sometimes the pressures are more subtle. More than one-third of seniors in last year's Investor Protection Trust study said they were being targeted by "people (who) are calling me or mailing me asking for money, lotteries and other schemes." Only one in five of adult children surveyed realized their parents were being pressured by such pitches.

If they're being conned, parents or grandparents may become secretive or defensive about their finances, which can make it more difficult to figure out what's going on. Once you know, however, stopping it may not be easy. Even if they repeatedly fall for financial scams -- even those as obvious as a Nigerian email scheme -- that may not be enough to wrest control of seniors' finances from them.

Courts don't grant conservatorships or guardianships without "clear and convincing evidence" that the senior "has functional limitations and doesn't understand that they have functional limitations," Amoruso said. Being foolish with money or easily conned may not be enough to strip seniors of their right to manage their own affairs, he said.

So how can you protect parents or grandparents -- and later, yourself -- from financial abuse? The following can help:

• Talk to them. Discuss common scams, like the "Help me, Grandma!" ruse where people posing as grandchildren call, text or email asking for emergency funds. There is some evidence people become more trusting with age, and they may be less in touch with how scams are evolving.
• Know who's in their circle. Predators work most effectively when they can isolate their victims. If you can, make it a point to introduce yourself to your parents' or grandparents' new friends and financial advisers. If family members are being turned against you, go to a respected third party (a minister, friend or professional adviser) for help regaining their trust.
• Thoroughly vet caregivers. Pay for a professional background check that includes criminal records and credit reports. Take note if a caregiver refuses to leave the room when you visit or tries to limit access to a parent or grandparent, since that's often a sign of elder abuse. Consult the Eldercare Locator or an elder law attorney for help.
• Look for signs they're on a sucker list. One sign is a large volume of junk mail for sweepstakes, "free" trips and contests or cheap trinkets that indicate the family members are buying products to "win" a contest.
• Set up the right paperwork. A power of attorney designates a trusted person to handle someone's finances in case of incapacity. Ideally, that person would be required to regularly report to a family member or a professional adviser, such as an attorney or an accountant. Having such reporting requirements can make the task more difficult, Amoruso noted, and can reduce the pool of people willing to take on the job, but it does offer another layer of protection for the senior.
• Don't hesitate to act if you see signs of abuse. "Get the police involved" is Amoruso's advice when you suspect financial misuse. An adult protective services office can launch investigations of any kind of elder abuse, neglect and exploitation. If you're not sure where to turn, start with the Eldercare Locator.

Liz Weston is the Web's most-read personal-finance writer. She is the author of several books, most recently "The 10 Commandments of Money: Survive and Thrive in the New Economy" (find it on Bing). Weston's award-winning columns appear every Monday and Thursday, exclusively on MSN Money. Join the conversation and send in your financial questions on Liz Weston's Facebook fan page.

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