Hackers and Spammers give more attention to sites which are popular. This is the only sad part of having a popular site. The website development sites have automates systems which help wiping the fake accounts. Everything cannot be automated though. Below are few steps that you can follow to protect yourself.
Your password should be strong
Always have a unique, long and uncommon password so that nobody else takes over your account maliciously. Be aware of hacking tactics such as phishing. Always change your password every month and use a strong combination of alphabets/numbers and special symbols.
Ask to see analytics
While buying a site, ask your seller to link their Google Analytics to the auction. The website development system can then pull the data directly from Google Analytics via API.
Verify domain ownership from the seller
While buying a site, make sure that the seller is only the rightful owner of the domain being sold. This gives you a confidence of their originality.
Research
Check error log on your website. It will give you exact picture of where the vulnerabilities are and hire an expert to plug in the loophole.
