Ministers of Parliament in the UK are worried about the threats and abuse they face, including being sent pictures of decapitated bodies, being surreptitiously filmed and having dog mess smeared on their door.
SNP MP Dr Lisa Cameron said she had put in place extra security so her children could play safely in her garden. Conservative Scott Mann said someone threatened to nail bomb his office.
The Commons Deputy Speaker said some MPs had told him they would not run for office again because of safety fears.
The BBC carried out a survey of MPs in writing and by phone between May and July this year. Out of a total of 650, the number of respondents was 172. Of those, 139 said either they or their staff had faced abuse in the past year.
More than 60 percent of those who replied said they had been in contact with the police about threats in the last 12 months.
Separate analysis carried out by academics at the University of Sheffield looked at levels of abuse directed at MPs on Twitter.
Labour MP David Lammy, who is black, has received the most abuse of any MP on Twitter so far this year. On average, male MPs attract significantly more abuse than female ones. Conservative MPs, on average, attract significantly more abuse than Labour ones. Sexist abuse is the most prevalent, as compared with homophobia or racism.
Mr Lammy said: "I will not compromise what I say in public life and let the bullies win. But it saddens me greatly that this is a growing stain on our national democracy. It needs to be challenged and it needs to be dealt with."