Gathering data depends on nature of data, objective of the data collection and require information.
By the help of proposed a new information system the objective is to collect the data of the competitors' customer. This data can be use for business growth to build new customer which is not unethical according to the business point of view. This is one kind of strategy by which company trying to create new customer and identify the buying behavior and purchase pattern of the customer.
If the proposed questionnaire which related to personal and confidential information about the customer create ethical problems for the customer like total income, Purchasing power, Family details. Some time customers not comfortable to provide their personal information.
Collecting data of the competitors' also create ethical problem for data privacy because customers are asset of the company if you are collecting data about the customers which affect the business and market of the competitor.
Yes, it matter whether the customers are individual or business. If customers are individual easy to collect the data and this can affect indirectly to the competitors' business but in case of the business customer this affect the directly to the competitors business which is unethical. Customer is king and free to move any market and fulfill their needs from any source. In case of business customer, the customer has sound knowledge about the business model and company's strategy so in this case this can create ethical problem because this can be the reason of disclose of the personal and confidential data and information about the business.
Yes, collection of the data depends on the type of information because if the data is related to the personal life and confidential information then the customer is not interested to give information because all feel that there is no safety and security. If we collect information related business then business customer don't give business information because there might be the loss for the company and I might work for the core competence of the company and make my business grow into profits.
So to conclude I must say that if anyone collecting data or introducing any information system to collect the data the success and ethical issues depends on nature of data type of information defined segment and objectives of the data collection. So the first thing come that is questionnaires by which data gets collected from the customer or defined segments and target groups. They analyze the collected data which is also important because through analysis of data fulfils all the objectives and requirements' of the organization.